21983952861 has 12 divisors (see below), whose sum is σ = 34197260188. Its totient is φ = 13528586304.

The previous prime is 21983952827. The next prime is 21983952877. The reversal of 21983952861 is 16825938912.

21983952861 is a `hidden beast` number, since 2 + 198 + 395 + 2 + 8 + 61 = 666.

It can be written as a sum of positive squares in 2 ways, for example, as 8330030361 + 13653922500 = 91269^2 + 116850^2 .

It is not a de Polignac number, because 21983952861 - 2¹⁰ = 21983951837 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 21983952798 and 21983952807.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21983152861) 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, 93948400 + ... + 93948633.

Almost surely, 2^21983952861 is an apocalyptic number.

It is an amenable number.

21983952861 is a deficient number, since it is larger than the sum of its proper divisors (12213307327).

21983952861 is a wasteful number, since it uses less digits than its factorization.

21983952861 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 187897052 (or 187897049 counting only the distinct ones).

The product of its digits is 1866240, while the sum is 54.

The spelling of 21983952861 in words is "twenty-one billion, nine hundred eighty-three million, nine hundred fifty-two thousand, eight hundred sixty-one".