21894720 has 56 divisors (see below), whose sum is σ = 69518784. Its totient is φ = 5838336.

The previous prime is 21894703. The next prime is 21894737. The reversal of 21894720 is 2749812.

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (21894703) and next prime (21894737).

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, 10444 + ... + 12363.

Almost surely, 2^21894720 is an apocalyptic number.

21894720 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21894720 is an abundant number, since it is smaller than the sum of its proper divisors (47624064).

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

21894720 is a wasteful number, since it uses less digits than its factorization.

21894720 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 22827 (or 22817 counting only the distinct ones).

The product of its (nonzero) digits is 8064, while the sum is 33.

The square root of 21894720 is about 4679.1794152394. The cubic root of 21894720 is about 279.7562504543.

The spelling of 21894720 in words is "twenty-one million, eight hundred ninety-four thousand, seven hundred twenty".