21264285 has 32 divisors (see below), whose sum is σ = 39686400. Its totient is φ = 9718464.

The previous prime is 21264251. The next prime is 21264293. The reversal of 21264285 is 58246212.

It is not a de Polignac number, because 21264285 - 2⁷ = 21264157 is a prime.

It is a super-2 number, since 2×21264285² = 904339633122450, which contains 22 as substring.

It is a Curzon number.

It is a plaindrome in base 16.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 3079 + ... + 7211.

It is an arithmetic number, because the mean of its divisors is an integer number (1240200).

Almost surely, 2^21264285 is an apocalyptic number.

It is an amenable number.

21264285 is a deficient number, since it is larger than the sum of its proper divisors (18422115).

21264285 is an equidigital number, since it uses as much as digits as its factorization.

21264285 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4162 (or 4148 counting only the distinct ones).

The product of its digits is 7680, while the sum is 30.

The square root of 21264285 is about 4611.3213941342. The cubic root of 21264285 is about 277.0449648319.

The spelling of 21264285 in words is "twenty-one million, two hundred sixty-four thousand, two hundred eighty-five".