21391674 has 32 divisors (see below), whose sum is σ = 45121536. Its totient is φ = 6750960.

The previous prime is 21391651. The next prime is 21391703. The reversal of 21391674 is 47619312.

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, 7519 + ... + 9965.

It is an arithmetic number, because the mean of its divisors is an integer number (1410048).

Almost surely, 2^21391674 is an apocalyptic number.

21391674 is an abundant number, since it is smaller than the sum of its proper divisors (23729862).

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

21391674 is a wasteful number, since it uses less digits than its factorization.

21391674 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2530.

The product of its digits is 9072, while the sum is 33.

The square root of 21391674 is about 4625.1134040151. The cubic root of 21391674 is about 277.5970993698.

The spelling of 21391674 in words is "twenty-one million, three hundred ninety-one thousand, six hundred seventy-four".