21634806 has 32 divisors (see below), whose sum is σ = 46022400. Its totient is φ = 6760800.

The previous prime is 21634801. The next prime is 21634813. The reversal of 21634806 is 60843612.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21634801) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 10575 + ... + 12453.

It is an arithmetic number, because the mean of its divisors is an integer number (1438200).

Almost surely, 2^21634806 is an apocalyptic number.

21634806 is an abundant number, since it is smaller than the sum of its proper divisors (24387594).

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

21634806 is a wasteful number, since it uses less digits than its factorization.

21634806 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2004.

The product of its (nonzero) digits is 6912, while the sum is 30.

The square root of 21634806 is about 4651.3230375883. The cubic root of 21634806 is about 278.6448378339.

The spelling of 21634806 in words is "twenty-one million, six hundred thirty-four thousand, eight hundred six".