91197389 has 4 divisors (see below), whose sum is σ = 91230780. Its totient is φ = 91164000.

The previous prime is 91197383. The next prime is 91197391. The reversal of 91197389 is 98379119.

It is a happy number.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 56505289 + 34692100 = 7517^2 + 5890^2 .

It is a cyclic number.

It is not a de Polignac number, because 91197389 - 2²⁴ = 74420173 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 (91197383) 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, 12194 + ... + 18195.

It is an arithmetic number, because the mean of its divisors is an integer number (22807695).

Almost surely, 2^91197389 is an apocalyptic number.

It is an amenable number.

91197389 is a deficient number, since it is larger than the sum of its proper divisors (33391).

91197389 is a wasteful number, since it uses less digits than its factorization.

91197389 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 33390.

The product of its digits is 122472, while the sum is 47.

The square root of 91197389 is about 9549.7324046279. The cubic root of 91197389 is about 450.1191273087.

The spelling of 91197389 in words is "ninety-one million, one hundred ninety-seven thousand, three hundred eighty-nine".