221142400 has 96 divisors (see below), whose sum is σ = 565365600. Its totient is φ = 85370880.

The previous prime is 221142359. The next prime is 221142403. The reversal of 221142400 is 4241122.

It is a super-2 number, since 2×221142400² = 97807922155520000, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (16).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (221142403) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 91609 + ... + 93991.

It is an arithmetic number, because the mean of its divisors is an integer number (5889225).

Almost surely, 2^221142400 is an apocalyptic number.

221142400 is a gapful number since it is divisible by the number (20) 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 221142400, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (282682800).

221142400 is an abundant number, since it is smaller than the sum of its proper divisors (344223200).

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

221142400 is a wasteful number, since it uses less digits than its factorization.

221142400 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2436 (or 2419 counting only the distinct ones).

The product of its (nonzero) digits is 128, while the sum is 16.

The square root of 221142400 is about 14870.8574063502. The cubic root of 221142400 is about 604.7241872815.

Adding to 221142400 its reverse (4241122), we get a palindrome (225383522).

The spelling of 221142400 in words is "two hundred twenty-one million, one hundred forty-two thousand, four hundred".