91973687 has 6 divisors (see below), whose sum is σ = 99592992. Its totient is φ = 84898632.

The previous prime is 91973663. The next prime is 91973753. The reversal of 91973687 is 78637919.

It is not a de Polignac number, because 91973687 - 2²⁶ = 24864823 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (91973627) 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, 271943 + ... + 272280.

It is an arithmetic number, because the mean of its divisors is an integer number (16598832).

Almost surely, 2^91973687 is an apocalyptic number.

91973687 is a deficient number, since it is larger than the sum of its proper divisors (7619305).

91973687 is a wasteful number, since it uses less digits than its factorization.

91973687 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 544249 (or 544236 counting only the distinct ones).

The product of its digits is 571536, while the sum is 50.

The square root of 91973687 is about 9590.2912885897. The cubic root of 91973687 is about 451.3927009337.

The spelling of 91973687 in words is "ninety-one million, nine hundred seventy-three thousand, six hundred eighty-seven".