91712991 has 8 divisors (see below), whose sum is σ = 122332464. Its totient is φ = 61117760.

The previous prime is 91712953. The next prime is 91713001. The reversal of 91712991 is 19921719.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 91712991 - 2⁹ = 91712479 is a prime.

It is a super-2 number, since 2×91712991² = 16822545436332162, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (91710991) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 6475 + ... + 15011.

It is an arithmetic number, because the mean of its divisors is an integer number (15291558).

Almost surely, 2^91712991 is an apocalyptic number.

91712991 is a deficient number, since it is larger than the sum of its proper divisors (30619473).

91712991 is a wasteful number, since it uses less digits than its factorization.

91712991 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 12121.

The product of its digits is 10206, while the sum is 39.

The square root of 91712991 is about 9576.6899814080. The cubic root of 91712991 is about 450.9658120636.

The spelling of 91712991 in words is "ninety-one million, seven hundred twelve thousand, nine hundred ninety-one".