21775473 has 12 divisors (see below), whose sum is σ = 32618768. Its totient is φ = 14516820.

The previous prime is 21775471. The next prime is 21775489. The reversal of 21775473 is 37457712.

It is not a de Polignac number, because 21775473 - 2¹ = 21775471 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21775471) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 44563 + ... + 45048.

Almost surely, 2^21775473 is an apocalyptic number.

It is an amenable number.

21775473 is a deficient number, since it is larger than the sum of its proper divisors (10843295).

21775473 is an frugal number, since it uses more digits than its factorization.

21775473 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 89626 (or 89614 counting only the distinct ones).

The product of its digits is 41160, while the sum is 36.

The square root of 21775473 is about 4666.4197196566. The cubic root of 21775473 is about 279.2474391754.

The spelling of 21775473 in words is "twenty-one million, seven hundred seventy-five thousand, four hundred seventy-three".