21412865 has 16 divisors (see below), whose sum is σ = 26732160. Its totient is φ = 16452480.

The previous prime is 21412849. The next prime is 21412883. The reversal of 21412865 is 56821412.

It is not a de Polignac number, because 21412865 - 2⁴ = 21412849 is a prime.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 12956 + ... + 14514.

It is an arithmetic number, because the mean of its divisors is an integer number (1670760).

Almost surely, 2^21412865 is an apocalyptic number.

It is an amenable number.

21412865 is a deficient number, since it is larger than the sum of its proper divisors (5319295).

21412865 is a wasteful number, since it uses less digits than its factorization.

21412865 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1672.

The product of its digits is 3840, while the sum is 29.

The square root of 21412865 is about 4627.4036997003. The cubic root of 21412865 is about 277.6887334442.

The spelling of 21412865 in words is "twenty-one million, four hundred twelve thousand, eight hundred sixty-five".