21939594 has 24 divisors (see below), whose sum is σ = 45114048. Its totient is φ = 7112880.

The previous prime is 21939581. The next prime is 21939607. The reversal of 21939594 is 49593912.

21939594 = 72² + 73² + ... + 404².

It is an interprime number because it is at equal distance from previous prime (21939581) and next prime (21939607).

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 6879 + ... + 9549.

It is an arithmetic number, because the mean of its divisors is an integer number (1879752).

Almost surely, 2^21939594 is an apocalyptic number.

21939594 is an abundant number, since it is smaller than the sum of its proper divisors (23174454).

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

21939594 is a wasteful number, since it uses less digits than its factorization.

21939594 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2750 (or 2713 counting only the distinct ones).

The product of its digits is 87480, while the sum is 42.

The square root of 21939594 is about 4683.9720323674. The cubic root of 21939594 is about 279.9472434618.

The spelling of 21939594 in words is "twenty-one million, nine hundred thirty-nine thousand, five hundred ninety-four".