21123264 has 28 divisors (see below), whose sum is σ = 55889144. Its totient is φ = 7041024.

The previous prime is 21123211. The next prime is 21123287. The reversal of 21123264 is 46232112.

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

It is a self number, because there is not a number n which added to its sum of digits gives 21123264.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 54817 + ... + 55200.

Almost surely, 2^21123264 is an apocalyptic number.

21123264 is a gapful number since it is divisible by the number (24) formed by its first and last digit.

It is an amenable number.

21123264 is an abundant number, since it is smaller than the sum of its proper divisors (34765880).

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

21123264 is a wasteful number, since it uses less digits than its factorization.

21123264 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 110032 (or 110022 counting only the distinct ones).

The product of its digits is 576, while the sum is 21.

The square root of 21123264 is about 4596.0052219291. The cubic root of 21123264 is about 276.4311681269.

Adding to 21123264 its reverse (46232112), we get a palindrome (67355376).

The spelling of 21123264 in words is "twenty-one million, one hundred twenty-three thousand, two hundred sixty-four".