91723940571 has 32 divisors (see below), whose sum is σ = 125968296960. Its totient is φ = 59333901984.

The previous prime is 91723940557. The next prime is 91723940611. The reversal of 91723940571 is 17504932719.

It is not a de Polignac number, because 91723940571 - 2²¹ = 91721843419 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 91723940571.

It is not an unprimeable number, because it can be changed into a prime (91723920571) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 44033496 + ... + 44035578.

It is an arithmetic number, because the mean of its divisors is an integer number (3936509280).

Almost surely, 2^91723940571 is an apocalyptic number.

91723940571 is a deficient number, since it is larger than the sum of its proper divisors (34244356389).

91723940571 is a wasteful number, since it uses less digits than its factorization.

91723940571 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4215.

The product of its (nonzero) digits is 476280, while the sum is 48.

The spelling of 91723940571 in words is "ninety-one billion, seven hundred twenty-three million, nine hundred forty thousand, five hundred seventy-one".