21912942 has 32 divisors (see below), whose sum is σ = 45196704. Its totient is φ = 7078400.

The previous prime is 21912931. The next prime is 21912967. The reversal of 21912942 is 24921912.

It is a happy number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 68968 + ... + 69284.

It is an arithmetic number, because the mean of its divisors is an integer number (1412397).

Almost surely, 2^21912942 is an apocalyptic number.

21912942 is an abundant number, since it is smaller than the sum of its proper divisors (23283762).

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

21912942 is a wasteful number, since it uses less digits than its factorization.

21912942 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 644.

The product of its digits is 2592, while the sum is 30.

The square root of 21912942 is about 4681.1261465592. The cubic root of 21912942 is about 279.8338384884.

The spelling of 21912942 in words is "twenty-one million, nine hundred twelve thousand, nine hundred forty-two".