90442809 has 24 divisors (see below), whose sum is σ = 133783104. Its totient is φ = 58860000.

The previous prime is 90442789. The next prime is 90442813. The reversal of 90442809 is 90824409.

It is a happy number.

It is not a de Polignac number, because 90442809 - 2⁵ = 90442777 is a prime.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (90442819) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 82354 + ... + 83444.

It is an arithmetic number, because the mean of its divisors is an integer number (5574296).

Almost surely, 2^90442809 is an apocalyptic number.

It is an amenable number.

90442809 is a deficient number, since it is larger than the sum of its proper divisors (43340295).

90442809 is a wasteful number, since it uses less digits than its factorization.

90442809 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1309 (or 1306 counting only the distinct ones).

The product of its (nonzero) digits is 20736, while the sum is 36.

The square root of 90442809 is about 9510.1424279555. The cubic root of 90442809 is about 448.8742378885.

The spelling of 90442809 in words is "ninety million, four hundred forty-two thousand, eight hundred nine".