91640979896 has 8 divisors (see below), whose sum is σ = 171826837320. Its totient is φ = 45820489944.

The previous prime is 91640979893. The next prime is 91640979953. The reversal of 91640979896 is 69897904619.

It is a tau number, because it is divible by the number of its divisors (8).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (91640979893) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5727561236 + ... + 5727561251.

It is an arithmetic number, because the mean of its divisors is an integer number (21478354665).

Almost surely, 2^91640979896 is an apocalyptic number.

It is an amenable number.

91640979896 is a deficient number, since it is larger than the sum of its proper divisors (80185857424).

91640979896 is a wasteful number, since it uses less digits than its factorization.

91640979896 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 11455122493 (or 11455122489 counting only the distinct ones).

The product of its (nonzero) digits is 52907904, while the sum is 68.

The spelling of 91640979896 in words is "ninety-one billion, six hundred forty million, nine hundred seventy-nine thousand, eight hundred ninety-six".