91639497 has 8 divisors (see below), whose sum is σ = 123267744. Its totient is φ = 60552128.

The previous prime is 91639481. The next prime is 91639501. The reversal of 91639497 is 79493619.

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 91639497 - 2⁴ = 91639481 is a prime.

It is not an unprimeable number, because it can be changed into a prime (91639477) 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, 134823 + ... + 135500.

It is an arithmetic number, because the mean of its divisors is an integer number (15408468).

Almost surely, 2^91639497 is an apocalyptic number.

It is an amenable number.

91639497 is a deficient number, since it is larger than the sum of its proper divisors (31628247).

91639497 is a wasteful number, since it uses less digits than its factorization.

91639497 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 270439.

The product of its digits is 367416, while the sum is 48.

The square root of 91639497 is about 9572.8520828434. The cubic root of 91639497 is about 450.8453197245.

The spelling of 91639497 in words is "ninety-one million, six hundred thirty-nine thousand, four hundred ninety-seven".