221434440 has 64 divisors (see below), whose sum is σ = 680520960. Its totient is φ = 57607680.

The previous prime is 221434361. The next prime is 221434471. The reversal of 221434440 is 44434122.

It is a happy number.

It is a super-2 number, since 2×221434440² = 98066422436227200, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (24).

It is a self number, because there is not a number n which added to its sum of digits gives 221434440.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 17584 + ... + 27423.

It is an arithmetic number, because the mean of its divisors is an integer number (10633140).

Almost surely, 2^221434440 is an apocalyptic number.

221434440 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

221434440 is an abundant number, since it is smaller than the sum of its proper divisors (459086520).

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

221434440 is a wasteful number, since it uses less digits than its factorization.

221434440 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 45062 (or 45058 counting only the distinct ones).

The product of its (nonzero) digits is 3072, while the sum is 24.

The square root of 221434440 is about 14880.6733718606. The cubic root of 221434440 is about 604.9902691785.

Adding to 221434440 its reverse (44434122), we get a palindrome (265868562).

The spelling of 221434440 in words is "two hundred twenty-one million, four hundred thirty-four thousand, four hundred forty".