21784852971 has 48 divisors (see below), whose sum is σ = 37891959040. Its totient is φ = 11781806400.

The previous prime is 21784852951. The next prime is 21784853003. The reversal of 21784852971 is 17925848712.

21784852971 is a `hidden beast` number, since 2 + 1 + 7 + 8 + 48 + 529 + 71 = 666.

It is not a de Polignac number, because 21784852971 - 2²⁵ = 21751298539 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21784852951) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 1299996 + ... + 1316646.

Almost surely, 2^21784852971 is an apocalyptic number.

21784852971 is a gapful number since it is divisible by the number (21) formed by its first and last digit.

21784852971 is a deficient number, since it is larger than the sum of its proper divisors (16107106069).

21784852971 is a wasteful number, since it uses less digits than its factorization.

21784852971 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 17776 (or 17773 counting only the distinct ones).

The product of its digits is 2257920, while the sum is 54.

The spelling of 21784852971 in words is "twenty-one billion, seven hundred eighty-four million, eight hundred fifty-two thousand, nine hundred seventy-one".