79890191 has 4 divisors (see below), whose sum is σ = 84589632. Its totient is φ = 75190752.

The previous prime is 79890169. The next prime is 79890211. The reversal of 79890191 is 19109897.

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

It is a cyclic number.

It is not a de Polignac number, because 79890191 - 2⁶ = 79890127 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 (79890101) 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, 2349695 + ... + 2349728.

It is an arithmetic number, because the mean of its divisors is an integer number (21147408).

Almost surely, 2^79890191 is an apocalyptic number.

79890191 is a deficient number, since it is larger than the sum of its proper divisors (4699441).

79890191 is a wasteful number, since it uses less digits than its factorization.

79890191 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4699440.

The product of its (nonzero) digits is 40824, while the sum is 44.

The square root of 79890191 is about 8938.1312923899. The cubic root of 79890191 is about 430.6897008030.

The spelling of 79890191 in words is "seventy-nine million, eight hundred ninety thousand, one hundred ninety-one".