90445509 has 24 divisors (see below), whose sum is σ = 162881472. Its totient is φ = 46984320.

The previous prime is 90445483. The next prime is 90445513. The reversal of 90445509 is 90554409.

It is not a de Polignac number, because 90445509 - 2⁵ = 90445477 is a prime.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (90445309) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 64564 + ... + 65949.

It is an arithmetic number, because the mean of its divisors is an integer number (6786728).

Almost surely, 2^90445509 is an apocalyptic number.

90445509 is a gapful number since it is divisible by the number (99) formed by its first and last digit.

It is an amenable number.

90445509 is a deficient number, since it is larger than the sum of its proper divisors (72435963).

90445509 is a wasteful number, since it uses less digits than its factorization.

90445509 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 130537 (or 130534 counting only the distinct ones).

The product of its (nonzero) digits is 32400, while the sum is 36.

The square root of 90445509 is about 9510.2843806061. The cubic root of 90445509 is about 448.8787046095.

Subtracting 90445509 from its reverse (90554409), we obtain a square (108900 = 330²).

The spelling of 90445509 in words is "ninety million, four hundred forty-five thousand, five hundred nine".