91639556980 has 24 divisors (see below), whose sum is σ = 192461558688. Its totient is φ = 36652301088.

The previous prime is 91639556977. The next prime is 91639557017. The reversal of 91639556980 is 8965593619.

It is a congruent number.

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, 1434 + ... + 428113.

It is an arithmetic number, because the mean of its divisors is an integer number (8019231612).

Almost surely, 2^91639556980 is an apocalyptic number.

It is an amenable number.

91639556980 is an abundant number, since it is smaller than the sum of its proper divisors (100822001708).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

91639556980 is a wasteful number, since it uses less digits than its factorization.

91639556980 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 440223 (or 440221 counting only the distinct ones).

The product of its (nonzero) digits is 15746400, while the sum is 61.

The spelling of 91639556980 in words is "ninety-one billion, six hundred thirty-nine million, five hundred fifty-six thousand, nine hundred eighty".