21905226 has 24 divisors (see below), whose sum is σ = 54241824. Its totient is φ = 6258600.

The previous prime is 21905209. The next prime is 21905227. The reversal of 21905226 is 62250912.

It is a super-2 number, since 2×21905226² = 959677852222152, which contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 21905226.

It is not an unprimeable number, because it can be changed into a prime (21905227) 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, 86800 + ... + 87051.

It is an arithmetic number, because the mean of its divisors is an integer number (2260076).

Almost surely, 2^21905226 is an apocalyptic number.

21905226 is an abundant number, since it is smaller than the sum of its proper divisors (32336598).

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

21905226 is a wasteful number, since it uses less digits than its factorization.

21905226 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 173866 (or 173863 counting only the distinct ones).

The product of its (nonzero) digits is 2160, while the sum is 27.

The square root of 21905226 is about 4680.3019133385. The cubic root of 21905226 is about 279.8009895389.

The spelling of 21905226 in words is "twenty-one million, nine hundred five thousand, two hundred twenty-six".