91716381 has 10 divisors (see below), whose sum is σ = 137008542. Its totient is φ = 61144200.

The previous prime is 91716379. The next prime is 91716389. The reversal of 91716381 is 18361719.

91716381 is a `hidden beast` number, since 9 + 17 + 1 + 638 + 1 = 666.

It can be written as a sum of positive squares in only one way, i.e., 69305625 + 22410756 = 8325^2 + 4734^2 .

It is not a de Polignac number, because 91716381 - 2¹ = 91716379 is a prime.

It is a super-2 number, since 2×91716381² = 16823789087474322, which contains 22 as substring.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (91716389) by changing a digit.

It is a polite number, since it can be written in 9 ways as a sum of consecutive naturals, for example, 566070 + ... + 566231.

Almost surely, 2^91716381 is an apocalyptic number.

It is an amenable number.

91716381 is a deficient number, since it is larger than the sum of its proper divisors (45292161).

91716381 is a wasteful number, since it uses less digits than its factorization.

91716381 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1132313 (or 1132304 counting only the distinct ones).

The product of its digits is 9072, while the sum is 36.

The square root of 91716381 is about 9576.8669720321. The cubic root of 91716381 is about 450.9713683657.

The spelling of 91716381 in words is "ninety-one million, seven hundred sixteen thousand, three hundred eighty-one".