81604949097 has 16 divisors (see below), whose sum is σ = 124395073920. Its totient is φ = 46614646272.

The previous prime is 81604949071. The next prime is 81604949119. The reversal of 81604949097 is 79094940618.

It is not a de Polignac number, because 81604949097 - 2⁶ = 81604949033 is a prime.

It is a super-2 number, since 2×81604949097² (a number of 23 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (81604948097) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 638088 + ... + 755225.

It is an arithmetic number, because the mean of its divisors is an integer number (7774692120).

Almost surely, 2^81604949097 is an apocalyptic number.

It is an amenable number.

81604949097 is a deficient number, since it is larger than the sum of its proper divisors (42790124823).

81604949097 is a wasteful number, since it uses less digits than its factorization.

81604949097 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1396112.

The product of its (nonzero) digits is 3919104, while the sum is 57.

The spelling of 81604949097 in words is "eighty-one billion, six hundred four million, nine hundred forty-nine thousand, ninety-seven".