91628189 has 4 divisors (see below), whose sum is σ = 91647360. Its totient is φ = 91609020.

The previous prime is 91628179. The next prime is 91628191. The reversal of 91628189 is 98182619.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 98182619 = 157 ⋅625367.

It is a cyclic number.

It is not a de Polignac number, because 91628189 - 2²⁴ = 74850973 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (91628179) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 4052 + ... + 14130.

It is an arithmetic number, because the mean of its divisors is an integer number (22911840).

Almost surely, 2^91628189 is an apocalyptic number.

It is an amenable number.

91628189 is a deficient number, since it is larger than the sum of its proper divisors (19171).

91628189 is a wasteful number, since it uses less digits than its factorization.

91628189 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 19170.

The product of its digits is 62208, while the sum is 44.

The square root of 91628189 is about 9572.2614360453. The cubic root of 91628189 is about 450.8267747057.

The spelling of 91628189 in words is "ninety-one million, six hundred twenty-eight thousand, one hundred eighty-nine".