21264868 has 12 divisors (see below), whose sum is σ = 38005632. Its totient is φ = 10406120.

The previous prime is 21264863. The next prime is 21264869. The reversal of 21264868 is 86846212.

It is a super-2 number, since 2×21264868² = 904389222114848, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (21264863) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 56368 + ... + 56743.

It is an arithmetic number, because the mean of its divisors is an integer number (3167136).

Almost surely, 2^21264868 is an apocalyptic number.

It is an amenable number.

21264868 is a deficient number, since it is larger than the sum of its proper divisors (16740764).

21264868 is a wasteful number, since it uses less digits than its factorization.

21264868 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 113162 (or 113160 counting only the distinct ones).

The product of its digits is 36864, while the sum is 37.

The square root of 21264868 is about 4611.3846076856. The cubic root of 21264868 is about 277.0474967101.

The spelling of 21264868 in words is "twenty-one million, two hundred sixty-four thousand, eight hundred sixty-eight".