21263912 has 32 divisors (see below), whose sum is σ = 41164200. Its totient is φ = 10291200.

The previous prime is 21263909. The next prime is 21263927. The reversal of 21263912 is 21936212.

It can be written as a sum of positive squares in 4 ways, for example, as 10201636 + 11062276 = 3194^2 + 3326^2 .

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 78914 + ... + 79182.

Almost surely, 2^21263912 is an apocalyptic number.

It is an amenable number.

21263912 is a deficient number, since it is larger than the sum of its proper divisors (19900288).

21263912 is a wasteful number, since it uses less digits than its factorization.

21263912 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 557 (or 553 counting only the distinct ones).

The product of its digits is 1296, while the sum is 26.

The square root of 21263912 is about 4611.2809500181. The cubic root of 21263912 is about 277.0433449267.

The spelling of 21263912 in words is "twenty-one million, two hundred sixty-three thousand, nine hundred twelve".