21912174 has 16 divisors (see below), whose sum is σ = 48693840. Its totient is φ = 7304040.

The previous prime is 21912173. The next prime is 21912179. The reversal of 21912174 is 47121912.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21912173) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 202837 + ... + 202944.

It is an arithmetic number, because the mean of its divisors is an integer number (3043365).

Almost surely, 2^21912174 is an apocalyptic number.

21912174 is an abundant number, since it is smaller than the sum of its proper divisors (26781666).

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

21912174 is a wasteful number, since it uses less digits than its factorization.

21912174 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 405792 (or 405786 counting only the distinct ones).

The product of its digits is 1008, while the sum is 27.

The square root of 21912174 is about 4681.0441142976. The cubic root of 21912174 is about 279.8305692652.

The spelling of 21912174 in words is "twenty-one million, nine hundred twelve thousand, one hundred seventy-four".