91579009 has 2 divisors, whose sum is σ = 91579010. Its totient is φ = 91579008.

The previous prime is 91579003. The next prime is 91579027. The reversal of 91579009 is 90097519.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 68807025 + 22771984 = 8295^2 + 4772^2 .

It is a cyclic number.

It is not a de Polignac number, because 91579009 - 2³ = 91579001 is a prime.

It is not a weakly prime, because it can be changed into another prime (91579001) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 45789504 + 45789505.

It is an arithmetic number, because the mean of its divisors is an integer number (45789505).

Almost surely, 2^91579009 is an apocalyptic number.

It is an amenable number.

91579009 is a deficient number, since it is larger than the sum of its proper divisors (1).

91579009 is an equidigital number, since it uses as much as digits as its factorization.

91579009 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 25515, while the sum is 40.

The square root of 91579009 is about 9569.6922103065. The cubic root of 91579009 is about 450.7461021930.

The spelling of 91579009 in words is "ninety-one million, five hundred seventy-nine thousand, nine".