91311321512 has 8 divisors (see below), whose sum is σ = 171208727850. Its totient is φ = 45655660752.

The previous prime is 91311321509. The next prime is 91311321581. The reversal of 91311321512 is 21512311319.

It can be written as a sum of positive squares in only one way, i.e., 89524230436 + 1787091076 = 299206^2 + 42274^2 .

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

It is a super-2 number, since 2×91311321512² (a number of 23 digits) contains 22 as substring.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5706957587 + ... + 5706957602.

Almost surely, 2^91311321512 is an apocalyptic number.

It is an amenable number.

91311321512 is a deficient number, since it is larger than the sum of its proper divisors (79897406338).

91311321512 is a wasteful number, since it uses less digits than its factorization.

91311321512 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 11413915195 (or 11413915191 counting only the distinct ones).

The product of its digits is 1620, while the sum is 29.

The spelling of 91311321512 in words is "ninety-one billion, three hundred eleven million, three hundred twenty-one thousand, five hundred twelve".