91755921 has 16 divisors (see below), whose sum is σ = 129038400. Its totient is φ = 57835008.

The previous prime is 91755871. The next prime is 91755929. The reversal of 91755921 is 12955719.

It is not a de Polignac number, because 91755921 - 2⁶ = 91755857 is a prime.

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 91755921.

It is not an unprimeable number, because it can be changed into a prime (91755929) 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, 33865 + ... + 36473.

It is an arithmetic number, because the mean of its divisors is an integer number (8064900).

Almost surely, 2^91755921 is an apocalyptic number.

It is an amenable number.

91755921 is a deficient number, since it is larger than the sum of its proper divisors (37282479).

91755921 is a wasteful number, since it uses less digits than its factorization.

91755921 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3248.

The product of its digits is 28350, while the sum is 39.

The square root of 91755921 is about 9578.9310990319. The cubic root of 91755921 is about 451.0361653914.

The spelling of 91755921 in words is "ninety-one million, seven hundred fifty-five thousand, nine hundred twenty-one".