91328644 has 24 divisors (see below), whose sum is σ = 176089536. Its totient is φ = 41100000.

The previous prime is 91328639. The next prime is 91328647. The reversal of 91328644 is 44682319.

91328644 = 391² + 392² + ... + 693².

It is not an unprimeable number, because it can be changed into a prime (91328647) 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, 5832 + ... + 14719.

It is an arithmetic number, because the mean of its divisors is an integer number (7337064).

Almost surely, 2^91328644 is an apocalyptic number.

It is an amenable number.

91328644 is a deficient number, since it is larger than the sum of its proper divisors (84760892).

91328644 is a wasteful number, since it uses less digits than its factorization.

91328644 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 20667 (or 20665 counting only the distinct ones).

The product of its digits is 41472, while the sum is 37.

The square root of 91328644 is about 9556.6021158150. The cubic root of 91328644 is about 450.3349670592.

The spelling of 91328644 in words is "ninety-one million, three hundred twenty-eight thousand, six hundred forty-four".