16221256 has 24 divisors (see below), whose sum is σ = 31803030. Its totient is φ = 7755968.

The previous prime is 16221253. The next prime is 16221311. The reversal of 16221256 is 65212261.

It can be written as a sum of positive squares in only one way, i.e., 15288100 + 933156 = 3910^2 + 966^2 .

It is a self number, because there is not a number n which added to its sum of digits gives 16221256.

It is not an unprimeable number, because it can be changed into a prime (16221253) 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 5 ways as a sum of consecutive naturals, for example, 2316 + ... + 6148.

Almost surely, 2^16221256 is an apocalyptic number.

It is an amenable number.

16221256 is a deficient number, since it is larger than the sum of its proper divisors (15581774).

16221256 is a wasteful number, since it uses less digits than its factorization.

16221256 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3885 (or 3858 counting only the distinct ones).

The product of its digits is 1440, while the sum is 25.

The square root of 16221256 is about 4027.5620417319. The cubic root of 16221256 is about 253.1404179198.

The spelling of 16221256 in words is "sixteen million, two hundred twenty-one thousand, two hundred fifty-six".