81598887279 has 24 divisors (see below), whose sum is σ = 145064689952. Its totient is φ = 43041170880.

The previous prime is 81598887269. The next prime is 81598887287. The reversal of 81598887279 is 97278889518.

81598887279 is a `hidden beast` number, since 8 + 1 + 598 + 8 + 8 + 7 + 27 + 9 = 666.

It is not a de Polignac number, because 81598887279 - 2⁷ = 81598887151 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81598887229) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 49815352 + ... + 49816989.

Almost surely, 2^81598887279 is an apocalyptic number.

81598887279 is a deficient number, since it is larger than the sum of its proper divisors (63465802673).

81598887279 is a wasteful number, since it uses less digits than its factorization.

81598887279 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 99632367 (or 99632364 counting only the distinct ones).

The product of its digits is 162570240, while the sum is 72.

The spelling of 81598887279 in words is "eighty-one billion, five hundred ninety-eight million, eight hundred eighty-seven thousand, two hundred seventy-nine".