221422464 has 128 divisors (see below), whose sum is σ = 662592000. Its totient is φ = 72783360.

The previous prime is 221422459. The next prime is 221422469. The reversal of 221422464 is 464224122.

221422464 is digitally balanced in base 3, because in such base it contains all the possibile digits an equal number of times.

It is an interprime number because it is at equal distance from previous prime (221422459) and next prime (221422469).

It is a tau number, because it is divible by the number of its divisors (128).

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a nude number because it is divisible by every one of its digits.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (221422469) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 272619 + ... + 273429.

It is an arithmetic number, because the mean of its divisors is an integer number (5176500).

Almost surely, 2^221422464 is an apocalyptic number.

221422464 is a gapful number since it is divisible by the number (24) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 221422464, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (331296000).

221422464 is an abundant number, since it is smaller than the sum of its proper divisors (441169536).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

221422464 is an equidigital number, since it uses as much as digits as its factorization.

221422464 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 913 (or 895 counting only the distinct ones).

The product of its digits is 6144, while the sum is 27.

The square root of 221422464 is about 14880.2709652748. The cubic root of 221422464 is about 604.9793622721.

Adding to 221422464 its reverse (464224122), we get a palindrome (685646586).

The spelling of 221422464 in words is "two hundred twenty-one million, four hundred twenty-two thousand, four hundred sixty-four".