81256866739194 has 32 divisors (see below), whose sum is σ = 162873821940480. Its totient is φ = 27025610764032.

The previous prime is 81256866739171. The next prime is 81256866739253. The reversal of 81256866739194 is 49193766865218.

It is a super-2 number, since 2×81256866739194² (a number of 29 digits) contains 22 as substring.

It is a Curzon number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 104227167 + ... + 105003885.

It is an arithmetic number, because the mean of its divisors is an integer number (5089806935640).

Almost surely, 2^{81256866739194} is an apocalyptic number.

81256866739194 is an abundant number, since it is smaller than the sum of its proper divisors (81616955201286).

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

81256866739194 is a wasteful number, since it uses less digits than its factorization.

81256866739194 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 815334.

The product of its digits is 940584960, while the sum is 75.

The spelling of 81256866739194 in words is "eighty-one trillion, two hundred fifty-six billion, eight hundred sixty-six million, seven hundred thirty-nine thousand, one hundred ninety-four".