90028202209 has 9 divisors (see below), whose sum is σ = 98960246931. Its totient is φ = 81840819720.

The previous prime is 90028202171. The next prime is 90028202221. The reversal of 90028202209 is 90220282009.

The square root of 90028202209 is 300047.

It is a perfect power (a square), and thus also a powerful number.

It can be written as a sum of positive squares in only one way, i.e., 18860902225 + 71167299984 = 137335^2 + 266772^2 .

It is a de Polignac number, because none of the positive numbers 2^k-90028202209 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (90028202809) by changing a digit.

It is a polite number, since it can be written in 8 ways as a sum of consecutive naturals, for example, 3286879 + ... + 3314155.

Almost surely, 2^90028202209 is an apocalyptic number.

90028202209 is the 300047-th square number.

90028202209 is the 150024-th centered octagonal number.

It is an amenable number.

90028202209 is a deficient number, since it is larger than the sum of its proper divisors (8932044722).

90028202209 is an frugal number, since it uses more digits than its factorization.

90028202209 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 54576 (or 27288 counting only the distinct ones).

The product of its (nonzero) digits is 10368, while the sum is 34.

The spelling of 90028202209 in words is "ninety billion, twenty-eight million, two hundred two thousand, two hundred nine".