21633854 has 16 divisors (see below), whose sum is σ = 35544960. Its totient is φ = 9793560.

The previous prime is 21633851. The next prime is 21633883. The reversal of 21633854 is 45833612.

It is a self number, because there is not a number n which added to its sum of digits gives 21633854.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21633851) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 3917 + ... + 7655.

It is an arithmetic number, because the mean of its divisors is an integer number (2221560).

Almost surely, 2^21633854 is an apocalyptic number.

21633854 is a deficient number, since it is larger than the sum of its proper divisors (13911106).

21633854 is a wasteful number, since it uses less digits than its factorization.

21633854 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4015.

The product of its digits is 17280, while the sum is 32.

The square root of 21633854 is about 4651.2206999883. The cubic root of 21633854 is about 278.6407506887.

The spelling of 21633854 in words is "twenty-one million, six hundred thirty-three thousand, eight hundred fifty-four".