91638501 has 16 divisors (see below), whose sum is σ = 129638400. Its totient is φ = 57416688.

The previous prime is 91638497. The next prime is 91638541. The reversal of 91638501 is 10583619.

It is not a de Polignac number, because 91638501 - 2² = 91638497 is a prime.

It is a super-2 number, since 2×91638501² = 16795229731054002, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (91638541) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 910 + ... + 13568.

It is an arithmetic number, because the mean of its divisors is an integer number (8102400).

Almost surely, 2^91638501 is an apocalyptic number.

It is an amenable number.

91638501 is a deficient number, since it is larger than the sum of its proper divisors (37999899).

91638501 is a wasteful number, since it uses less digits than its factorization.

91638501 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 12808.

The product of its (nonzero) digits is 6480, while the sum is 33.

The square root of 91638501 is about 9572.8000605883. The cubic root of 91638501 is about 450.8436863547.

The spelling of 91638501 in words is "ninety-one million, six hundred thirty-eight thousand, five hundred one".