21400264 has 16 divisors (see below), whose sum is σ = 40784220. Its totient is φ = 10524480.

The previous prime is 21400219. The next prime is 21400271. The reversal of 21400264 is 46200412.

It can be written as a sum of positive squares in 2 ways, for example, as 16337764 + 5062500 = 4042^2 + 2250^2 .

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 21439 + ... + 22414.

Almost surely, 2^21400264 is an apocalyptic number.

It is an amenable number.

21400264 is a deficient number, since it is larger than the sum of its proper divisors (19383956).

21400264 is a wasteful number, since it uses less digits than its factorization.

21400264 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 43920 (or 43916 counting only the distinct ones).

The product of its (nonzero) digits is 384, while the sum is 19.

The square root of 21400264 is about 4626.0419366884. The cubic root of 21400264 is about 277.6342515187.

Adding to 21400264 its reverse (46200412), we get a palindrome (67600676).

The spelling of 21400264 in words is "twenty-one million, four hundred thousand, two hundred sixty-four".