21912542 has 16 divisors (see below), whose sum is σ = 34192752. Its totient is φ = 10523520.

The previous prime is 21912521. The next prime is 21912563. The reversal of 21912542 is 24521912.

It is an interprime number because it is at equal distance from previous prime (21912521) and next prime (21912563).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 3158 + ... + 7334.

It is an arithmetic number, because the mean of its divisors is an integer number (2137047).

Almost surely, 2^21912542 is an apocalyptic number.

21912542 is a deficient number, since it is larger than the sum of its proper divisors (12280210).

21912542 is a wasteful number, since it uses less digits than its factorization.

21912542 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4283.

The product of its digits is 1440, while the sum is 26.

The square root of 21912542 is about 4681.0834216023. The cubic root of 21912542 is about 279.8321357775.

The spelling of 21912542 in words is "twenty-one million, nine hundred twelve thousand, five hundred forty-two".