21800472 has 16 divisors (see below), whose sum is σ = 54501240. Its totient is φ = 7266816.

The previous prime is 21800453. The next prime is 21800483. The reversal of 21800472 is 27400812.

It is a Harshad number since it is a multiple of its sum of digits (24), and also a Moran number because the ratio is a prime number: 908353 = 21800472 / (2 + 1 + 8 + 0 + 0 + 4 + 7 + 2).

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, 454153 + ... + 454200.

Almost surely, 2^21800472 is an apocalyptic number.

It is an amenable number.

21800472 is an abundant number, since it is smaller than the sum of its proper divisors (32700768).

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

21800472 is a wasteful number, since it uses less digits than its factorization.

21800472 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 908362 (or 908358 counting only the distinct ones).

The product of its (nonzero) digits is 896, while the sum is 24.

The square root of 21800472 is about 4669.0975573445. The cubic root of 21800472 is about 279.3542602304.

The spelling of 21800472 in words is "twenty-one million, eight hundred thousand, four hundred seventy-two".