91001664 has 112 divisors (see below), whose sum is σ = 288178240. Its totient is φ = 27993600.

The previous prime is 91001657. The next prime is 91001671. The reversal of 91001664 is 46610019.

It is an interprime number because it is at equal distance from previous prime (91001657) and next prime (91001671).

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 20439 + ... + 24489.

It is an arithmetic number, because the mean of its divisors is an integer number (2573020).

Almost surely, 2^91001664 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 91001664, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (144089120).

91001664 is an abundant number, since it is smaller than the sum of its proper divisors (197176576).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

91001664 is a wasteful number, since it uses less digits than its factorization.

91001664 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4085 (or 4069 counting only the distinct ones).

The product of its (nonzero) digits is 1296, while the sum is 27.

The square root of 91001664 is about 9539.4792310692. The cubic root of 91001664 is about 449.7968861132.

The spelling of 91001664 in words is "ninety-one million, one thousand, six hundred sixty-four".