81867879312336 has 240 divisors, whose sum is σ = 269682429219840. Its totient is φ = 22943559536640.

The previous prime is 81867879312313. The next prime is 81867879312337. The reversal of 81867879312336 is 63321397876818.

81867879312336 is a `hidden beast` number, since 8 + 186 + 7 + 87 + 9 + 31 + 2 + 336 = 666.

It is a Harshad number since it is a multiple of its sum of digits (72).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81867879312337) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 40505716 + ... + 42478803.

It is an arithmetic number, because the mean of its divisors is an integer number (1123676788416).

Almost surely, 2^{81867879312336} is an apocalyptic number.

It is an amenable number.

81867879312336 is an abundant number, since it is smaller than the sum of its proper divisors (187814549907504).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

81867879312336 is a wasteful number, since it uses less digits than its factorization.

81867879312336 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 82984594 (or 82984585 counting only the distinct ones).

The product of its digits is 438939648, while the sum is 72.

The spelling of 81867879312336 in words is "eighty-one trillion, eight hundred sixty-seven billion, eight hundred seventy-nine million, three hundred twelve thousand, three hundred thirty-six".