81171517106378 has 64 divisors (see below), whose sum is σ = 129453913169280. Its totient is φ = 38064813696000.

The previous prime is 81171517106363. The next prime is 81171517106389. The reversal of 81171517106378 is 87360171517118.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 3528724625 + ... + 3528747627.

It is an arithmetic number, because the mean of its divisors is an integer number (2022717393270).

Almost surely, 2^{81171517106378} is an apocalyptic number.

81171517106378 is a deficient number, since it is larger than the sum of its proper divisors (48282396062902).

81171517106378 is a wasteful number, since it uses less digits than its factorization.

81171517106378 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 24983.

The product of its (nonzero) digits is 1975680, while the sum is 56.

The spelling of 81171517106378 in words is "eighty-one trillion, one hundred seventy-one billion, five hundred seventeen million, one hundred six thousand, three hundred seventy-eight".