21894520 has 16 divisors (see below), whose sum is σ = 49262760. Its totient is φ = 8757792.

The previous prime is 21894511. The next prime is 21894563. The reversal of 21894520 is 2549812.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 273642 + ... + 273721.

Almost surely, 2^21894520 is an apocalyptic number.

21894520 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21894520 is an abundant number, since it is smaller than the sum of its proper divisors (27368240).

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

21894520 is a wasteful number, since it uses less digits than its factorization.

21894520 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 547374 (or 547370 counting only the distinct ones).

The product of its (nonzero) digits is 5760, while the sum is 31.

The square root of 21894520 is about 4679.1580439220. The cubic root of 21894520 is about 279.7553986292.

The spelling of 21894520 in words is "twenty-one million, eight hundred ninety-four thousand, five hundred twenty".