91506681 has 12 divisors (see below), whose sum is σ = 151058752. Its totient is φ = 52289496.

The previous prime is 91506677. The next prime is 91506683. The reversal of 91506681 is 18660519.

91506681 = T₂₅₉₀ + T₂₅₉₁ + ... + T₂₆₁₆.

91506681 is a `hidden beast` number, since 91 + 506 + 68 + 1 = 666.

It is not a de Polignac number, because 91506681 - 2² = 91506677 is a prime.

It is a super-2 number, since 2×91506681² = 16746945335271522, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (91506683) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 726181 + ... + 726306.

Almost surely, 2^91506681 is an apocalyptic number.

It is an amenable number.

91506681 is a deficient number, since it is larger than the sum of its proper divisors (59552071).

91506681 is a wasteful number, since it uses less digits than its factorization.

91506681 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1452500 (or 1452497 counting only the distinct ones).

The product of its (nonzero) digits is 12960, while the sum is 36.

The square root of 91506681 is about 9565.9124499443. The cubic root of 91506681 is about 450.6274063223.

The spelling of 91506681 in words is "ninety-one million, five hundred six thousand, six hundred eighty-one".