81671098975 has 24 divisors (see below), whose sum is σ = 102961432368. Its totient is φ = 64247635200.

The previous prime is 81671098961. The next prime is 81671098991. The reversal of 81671098975 is 57989017618.

It is not a de Polignac number, because 81671098975 - 2⁹ = 81671098463 is a prime.

It is a hoax number, since the sum of its digits (61) coincides with the sum of the digits of its distinct prime factors.

It is a Harshad number since it is a multiple of its sum of digits (61).

It is a Duffinian number.

It is a congruent number.

It is an unprimeable number.

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 23 ways as a sum of consecutive naturals, for example, 8622192 + ... + 8631658.

It is an arithmetic number, because the mean of its divisors is an integer number (4290059682).

Almost surely, 2^81671098975 is an apocalyptic number.

81671098975 is a deficient number, since it is larger than the sum of its proper divisors (21290333393).

81671098975 is a wasteful number, since it uses less digits than its factorization.

81671098975 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 15195 (or 15190 counting only the distinct ones).

The product of its (nonzero) digits is 7620480, while the sum is 61.

The spelling of 81671098975 in words is "eighty-one billion, six hundred seventy-one million, ninety-eight thousand, nine hundred seventy-five".