81708188079 has 8 divisors (see below), whose sum is σ = 124507715200. Its totient is φ = 46690393176.

The previous prime is 81708188071. The next prime is 81708188087. The reversal of 81708188079 is 97088180718.

It is an interprime number because it is at equal distance from previous prime (81708188071) and next prime (81708188087).

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 81708188079 - 2³ = 81708188071 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81708188071) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1945433029 + ... + 1945433070.

It is an arithmetic number, because the mean of its divisors is an integer number (15563464400).

Almost surely, 2^81708188079 is an apocalyptic number.

81708188079 is a deficient number, since it is larger than the sum of its proper divisors (42799527121).

81708188079 is a wasteful number, since it uses less digits than its factorization.

81708188079 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3890866109.

The product of its (nonzero) digits is 1806336, while the sum is 57.

The spelling of 81708188079 in words is "eighty-one billion, seven hundred eight million, one hundred eighty-eight thousand, seventy-nine".