81640795 has 8 divisors (see below), whose sum is σ = 98184240. Its totient is φ = 65169120.

The previous prime is 81640721. The next prime is 81640813. The reversal of 81640795 is 59704618.

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

It is not a de Polignac number, because 81640795 - 2⁷ = 81640667 is a prime.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 15405 + ... + 20014.

It is an arithmetic number, because the mean of its divisors is an integer number (12273030).

Almost surely, 2^81640795 is an apocalyptic number.

81640795 is a deficient number, since it is larger than the sum of its proper divisors (16543445).

81640795 is a wasteful number, since it uses less digits than its factorization.

81640795 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 35885.

The product of its (nonzero) digits is 60480, while the sum is 40.

The square root of 81640795 is about 9035.5295915624. The cubic root of 81640795 is about 433.8128462451.

It can be divided in two parts, 816 and 40795, that multiplied together give a triangular number (33288720 = T₈₁₅₉).

The spelling of 81640795 in words is "eighty-one million, six hundred forty thousand, seven hundred ninety-five".