82139520961 has 4 divisors (see below), whose sum is σ = 84359508052. Its totient is φ = 79919533872.

The previous prime is 82139520949. The next prime is 82139520971. The reversal of 82139520961 is 16902593128.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 76831524225 + 5307996736 = 277185^2 + 72856^2 .

It is a cyclic number.

It is not a de Polignac number, because 82139520961 - 2²³ = 82131132353 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (82139520971) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1109993490 + ... + 1109993563.

It is an arithmetic number, because the mean of its divisors is an integer number (21089877013).

Almost surely, 2^82139520961 is an apocalyptic number.

It is an amenable number.

82139520961 is a deficient number, since it is larger than the sum of its proper divisors (2219987091).

82139520961 is a wasteful number, since it uses less digits than its factorization.

82139520961 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2219987090.

The product of its (nonzero) digits is 233280, while the sum is 46.

The spelling of 82139520961 in words is "eighty-two billion, one hundred thirty-nine million, five hundred twenty thousand, nine hundred sixty-one".