90785309 has 4 divisors (see below), whose sum is σ = 93239004. Its totient is φ = 88331616.

The previous prime is 90785297. The next prime is 90785371. The reversal of 90785309 is 90358709.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 90358709 = 7 ⋅12908387.

It can be written as a sum of positive squares in 2 ways, for example, as 31956409 + 58828900 = 5653^2 + 7670^2 .

It is a cyclic number.

It is not a de Polignac number, because 90785309 - 2⁴ = 90785293 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 (90785509) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1226792 + ... + 1226865.

It is an arithmetic number, because the mean of its divisors is an integer number (23309751).

Almost surely, 2^90785309 is an apocalyptic number.

It is an amenable number.

90785309 is a deficient number, since it is larger than the sum of its proper divisors (2453695).

90785309 is a wasteful number, since it uses less digits than its factorization.

90785309 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2453694.

The product of its (nonzero) digits is 68040, while the sum is 41.

The square root of 90785309 is about 9528.1325032768. The cubic root of 90785309 is about 449.4401416125.

The spelling of 90785309 in words is "ninety million, seven hundred eighty-five thousand, three hundred nine".