81607790897 has 4 divisors (see below), whose sum is σ = 81661801536. Its totient is φ = 81553780260.

The previous prime is 81607790881. The next prime is 81607790921. The reversal of 81607790897 is 79809770618.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 81607790897 - 2⁴ = 81607790881 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (81607792897) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 27003053 + ... + 27006074.

It is an arithmetic number, because the mean of its divisors is an integer number (20415450384).

Almost surely, 2^81607790897 is an apocalyptic number.

It is an amenable number.

81607790897 is a deficient number, since it is larger than the sum of its proper divisors (54010639).

81607790897 is a wasteful number, since it uses less digits than its factorization.

81607790897 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 54010638.

The product of its (nonzero) digits is 10668672, while the sum is 62.

The spelling of 81607790897 in words is "eighty-one billion, six hundred seven million, seven hundred ninety thousand, eight hundred ninety-seven".