91628121 has 16 divisors (see below), whose sum is σ = 133801920. Its totient is φ = 55429440.

The previous prime is 91628107. The next prime is 91628137. The reversal of 91628121 is 12182619.

It is a happy number.

It is not a de Polignac number, because 91628121 - 2⁹ = 91627609 is a prime.

It is not an unprimeable number, because it can be changed into a prime (91628191) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 17610 + ... + 22211.

It is an arithmetic number, because the mean of its divisors is an integer number (8362620).

Almost surely, 2^91628121 is an apocalyptic number.

It is an amenable number.

91628121 is a deficient number, since it is larger than the sum of its proper divisors (42173799).

91628121 is a wasteful number, since it uses less digits than its factorization.

91628121 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 39896.

The product of its digits is 1728, while the sum is 30.

The square root of 91628121 is about 9572.2578841149. The cubic root of 91628121 is about 450.8266631817.

The spelling of 91628121 in words is "ninety-one million, six hundred twenty-eight thousand, one hundred twenty-one".