81947670032 has 10 divisors (see below), whose sum is σ = 158773610718. Its totient is φ = 40973835008.

The previous prime is 81947670031. The next prime is 81947670053. The reversal of 81947670032 is 23007674918.

It can be written as a sum of positive squares in only one way, i.e., 71729694976 + 10217975056 = 267824^2 + 101084^2 .

It is not an unprimeable number, because it can be changed into a prime (81947670031) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 2560864673 + ... + 2560864704.

Almost surely, 2^81947670032 is an apocalyptic number.

It is an amenable number.

81947670032 is a deficient number, since it is larger than the sum of its proper divisors (76825940686).

81947670032 is a wasteful number, since it uses less digits than its factorization.

81947670032 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5121729385 (or 5121729379 counting only the distinct ones).

The product of its (nonzero) digits is 508032, while the sum is 47.

The spelling of 81947670032 in words is "eighty-one billion, nine hundred forty-seven million, six hundred seventy thousand, thirty-two".