90979209 has 6 divisors (see below), whose sum is σ = 131414426. Its totient is φ = 60652800.

The previous prime is 90979171. The next prime is 90979219. The reversal of 90979209 is 90297909.

It can be written as a sum of positive squares in only one way, i.e., 89870400 + 1108809 = 9480^2 + 1053^2 .

It is not a de Polignac number, because 90979209 - 2⁷ = 90979081 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (90979219) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 5054392 + ... + 5054409.

Almost surely, 2^90979209 is an apocalyptic number.

It is an amenable number.

90979209 is a deficient number, since it is larger than the sum of its proper divisors (40435217).

90979209 is a wasteful number, since it uses less digits than its factorization.

90979209 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10108807 (or 10108804 counting only the distinct ones).

The product of its (nonzero) digits is 91854, while the sum is 45.

The square root of 90979209 is about 9538.3022074162. The cubic root of 90979209 is about 449.7598867167.

The spelling of 90979209 in words is "ninety million, nine hundred seventy-nine thousand, two hundred nine".