81135320837184 has 42 divisors (see below), whose sum is σ = 232559747748510. Its totient is φ = 27045106945536.

The previous prime is 81135320837177. The next prime is 81135320837191. The reversal of 81135320837184 is 48173802353118.

81135320837184 is a `hidden beast` number, since 8 + 1 + 1 + 353 + 208 + 3 + 7 + 1 + 84 = 666.

It is an interprime number because it is at equal distance from previous prime (81135320837177) and next prime (81135320837191).

It can be written as a sum of positive squares in only one way, i.e., 81117546614784 + 17774222400 = 9006528^2 + 133320^2 .

It is a self number, because there is not a number n which added to its sum of digits gives 81135320837184.

It is an unprimeable number.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 70429965429 + ... + 70429966580.

It is an arithmetic number, because the mean of its divisors is an integer number (5537136851155).

Almost surely, 2^{81135320837184} is an apocalyptic number.

It is an amenable number.

81135320837184 is an abundant number, since it is smaller than the sum of its proper divisors (151424426911326).

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

81135320837184 is a wasteful number, since it uses less digits than its factorization.

81135320837184 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 140859932027 (or 140859932014 counting only the distinct ones).

The product of its (nonzero) digits is 3870720, while the sum is 54.

The spelling of 81135320837184 in words is "eighty-one trillion, one hundred thirty-five billion, three hundred twenty million, eight hundred thirty-seven thousand, one hundred eighty-four".