21160864 has 24 divisors (see below), whose sum is σ = 41882400. Its totient is φ = 10524096.

The previous prime is 21160849. The next prime is 21160871. The reversal of 21160864 is 46806112.

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, 4707 + ... + 8029.

It is an arithmetic number, because the mean of its divisors is an integer number (1745100).

Almost surely, 2^21160864 is an apocalyptic number.

It is an amenable number.

21160864 is a deficient number, since it is larger than the sum of its proper divisors (20721536).

21160864 is a wasteful number, since it uses less digits than its factorization.

21160864 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3532 (or 3524 counting only the distinct ones).

The product of its (nonzero) digits is 2304, while the sum is 28.

The square root of 21160864 is about 4600.0939120848. The cubic root of 21160864 is about 276.5950893044.

Adding to 21160864 its reverse (46806112), we get a palindrome (67966976).

It can be divided in two parts, 211 and 60864, that added together give a triangular number (61075 = T₃₄₉).

The spelling of 21160864 in words is "twenty-one million, one hundred sixty thousand, eight hundred sixty-four".