21706552131 has 8 divisors (see below), whose sum is σ = 31573166784. Its totient is φ = 13155486120.

The previous prime is 21706552099. The next prime is 21706552159. The reversal of 21706552131 is 13125560712.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 21706552131 - 2⁵ = 21706552099 is a prime.

It is a super-2 number, since 2×21706552131² (a number of 21 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (33), and also a Moran number because the ratio is a prime number: 657774307 = 21706552131 / (2 + 1 + 7 + 0 + 6 + 5 + 5 + 2 + 1 + 3 + 1).

It is a junction number, because it is equal to n+sod(n) for n = 21706552092 and 21706552101.

It is not an unprimeable number, because it can be changed into a prime (21706551131) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 328887121 + ... + 328887186.

It is an arithmetic number, because the mean of its divisors is an integer number (3946645848).

Almost surely, 2^21706552131 is an apocalyptic number.

21706552131 is a deficient number, since it is larger than the sum of its proper divisors (9866614653).

21706552131 is a wasteful number, since it uses less digits than its factorization.

21706552131 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 657774321.

The product of its (nonzero) digits is 12600, while the sum is 33.

The spelling of 21706552131 in words is "twenty-one billion, seven hundred six million, five hundred fifty-two thousand, one hundred thirty-one".