91000121 has 16 divisors (see below), whose sum is σ = 97566336. Its totient is φ = 84686976.

The previous prime is 91000081. The next prime is 91000163. The reversal of 91000121 is 12100019.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-91000121 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 91000096 and 91000105.

It is not an unprimeable number, because it can be changed into a prime (91000171) 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, 139031 + ... + 139683.

It is an arithmetic number, because the mean of its divisors is an integer number (6097896).

Almost surely, 2^91000121 is an apocalyptic number.

It is an amenable number.

91000121 is a deficient number, since it is larger than the sum of its proper divisors (6566215).

91000121 is a wasteful number, since it uses less digits than its factorization.

91000121 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 832.

The product of its (nonzero) digits is 18, while the sum is 14.

The square root of 91000121 is about 9539.3983562906. The cubic root of 91000121 is about 449.7943438868.

The spelling of 91000121 in words is "ninety-one million, one hundred twenty-one", and thus it is an aban number.