21265600 has 42 divisors (see below), whose sum is σ = 52330604. Its totient is φ = 8505600.

The previous prime is 21265577. The next prime is 21265603. The reversal of 21265600 is 656212.

It is not an unprimeable number, because it can be changed into a prime (21265603) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 5046 + ... + 8245.

Almost surely, 2^21265600 is an apocalyptic number.

21265600 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21265600 is an abundant number, since it is smaller than the sum of its proper divisors (31065004).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21265600 is a wasteful number, since it uses less digits than its factorization.

21265600 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 13313 (or 13298 counting only the distinct ones).

The product of its (nonzero) digits is 720, while the sum is 22.

The square root of 21265600 is about 4611.4639757890. The cubic root of 21265600 is about 277.0506756066.

The spelling of 21265600 in words is "twenty-one million, two hundred sixty-five thousand, six hundred".