91089660657 has 16 divisors (see below), whose sum is σ = 123516489600. Its totient is φ = 59699539200.

The previous prime is 91089660617. The next prime is 91089660671. The reversal of 91089660657 is 75606698019.

It is a happy number.

It is not a de Polignac number, because 91089660657 - 2⁸ = 91089660401 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 91089660597 and 91089660606.

It is not an unprimeable number, because it can be changed into a prime (91089660617) 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, 538344 + ... + 687017.

It is an arithmetic number, because the mean of its divisors is an integer number (7719780600).

Almost surely, 2^91089660657 is an apocalyptic number.

It is an amenable number.

91089660657 is a deficient number, since it is larger than the sum of its proper divisors (32426828943).

91089660657 is a wasteful number, since it uses less digits than its factorization.

91089660657 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1225784.

The product of its (nonzero) digits is 4898880, while the sum is 57.

The spelling of 91089660657 in words is "ninety-one billion, eighty-nine million, six hundred sixty thousand, six hundred fifty-seven".