91292809 has 2 divisors, whose sum is σ = 91292810. Its totient is φ = 91292808.

The previous prime is 91292797. The next prime is 91292833. The reversal of 91292809 is 90829219.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 55830784 + 35462025 = 7472^2 + 5955^2 .

It is a cyclic number.

It is not a de Polignac number, because 91292809 - 2¹¹ = 91290761 is a prime.

It is a super-2 number, since 2×91292809² = 16668753950220962, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (91292849) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 45646404 + 45646405.

It is an arithmetic number, because the mean of its divisors is an integer number (45646405).

Almost surely, 2^91292809 is an apocalyptic number.

It is an amenable number.

91292809 is a deficient number, since it is larger than the sum of its proper divisors (1).

91292809 is an equidigital number, since it uses as much as digits as its factorization.

91292809 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 23328, while the sum is 40.

The square root of 91292809 is about 9554.7270499999. The cubic root of 91292809 is about 450.2760594191.

The spelling of 91292809 in words is "ninety-one million, two hundred ninety-two thousand, eight hundred nine".