21265363 has 12 divisors (see below), whose sum is σ = 25814160. Its totient is φ = 17434032.

The previous prime is 21265337. The next prime is 21265373. The reversal of 21265363 is 36356212.

It is not a de Polignac number, because 21265363 - 2⁹ = 21264851 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21265303) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 8308 + ... + 10561.

It is an arithmetic number, because the mean of its divisors is an integer number (2151180).

Almost surely, 2^21265363 is an apocalyptic number.

21265363 is a gapful number since it is divisible by the number (23) formed by its first and last digit.

21265363 is a deficient number, since it is larger than the sum of its proper divisors (4548797).

21265363 is a wasteful number, since it uses less digits than its factorization.

21265363 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 18906 (or 18899 counting only the distinct ones).

The product of its digits is 6480, while the sum is 28.

The square root of 21265363 is about 4611.4382788887. The cubic root of 21265363 is about 277.0496463817.

The spelling of 21265363 in words is "twenty-one million, two hundred sixty-five thousand, three hundred sixty-three".