91931693 has 6 divisors (see below), whose sum is σ = 106941006. Its totient is φ = 78798552.

The previous prime is 91931689. The next prime is 91931731. The reversal of 91931693 is 39613919.

It can be written as a sum of positive squares in only one way, i.e., 91431844 + 499849 = 9562^2 + 707^2 .

It is not a de Polignac number, because 91931693 - 2² = 91931689 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 91931693.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (91931093) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 938030 + ... + 938127.

It is an arithmetic number, because the mean of its divisors is an integer number (17823501).

Almost surely, 2^91931693 is an apocalyptic number.

It is an amenable number.

91931693 is a deficient number, since it is larger than the sum of its proper divisors (15009313).

91931693 is a wasteful number, since it uses less digits than its factorization.

91931693 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1876171 (or 1876164 counting only the distinct ones).

The product of its digits is 39366, while the sum is 41.

The square root of 91931693 is about 9588.1016369248. The cubic root of 91931693 is about 451.3239904455.

The spelling of 91931693 in words is "ninety-one million, nine hundred thirty-one thousand, six hundred ninety-three".