91997714518 has 16 divisors (see below), whose sum is σ = 139960154880. Its totient is φ = 45344514600.

The previous prime is 91997714443. The next prime is 91997714521. The reversal of 91997714518 is 81541779919.

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, 1042333 + ... + 1127143.

It is an arithmetic number, because the mean of its divisors is an integer number (8747509680).

Almost surely, 2^91997714518 is an apocalyptic number.

91997714518 is a deficient number, since it is larger than the sum of its proper divisors (47962440362).

91997714518 is a wasteful number, since it uses less digits than its factorization.

91997714518 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 92523.

The product of its digits is 5715360, while the sum is 61.

The spelling of 91997714518 in words is "ninety-one billion, nine hundred ninety-seven million, seven hundred fourteen thousand, five hundred eighteen".