90572708209 has 3 divisors (see below), whose sum is σ = 90573009163. Its totient is φ = 90572407256.

The previous prime is 90572708197. The next prime is 90572708249. The reversal of 90572708209 is 90280727509.

The square root of 90572708209 is 300953.

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

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It can be written as a sum of positive squares in only one way, i.e., 49878522225 + 40694185984 = 223335^2 + 201728^2 .

It is not a de Polignac number, because 90572708209 - 2³³ = 81982773617 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (90572708249) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 2 ways as a sum of consecutive naturals, for example, 150477 + ... + 451429.

Almost surely, 2^90572708209 is an apocalyptic number.

90572708209 is the 300953-rd square number.

90572708209 is the 150477-th centered octagonal number.

It is an amenable number.

90572708209 is a deficient number, since it is larger than the sum of its proper divisors (300954).

90572708209 is an frugal number, since it uses more digits than its factorization.

90572708209 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 601906 (or 300953 counting only the distinct ones).

The product of its (nonzero) digits is 635040, while the sum is 49.

Multiplying 90572708209 by its sum of digits (49), we get a square (4438062702241 = 2106671²).

The spelling of 90572708209 in words is "ninety billion, five hundred seventy-two million, seven hundred eight thousand, two hundred nine".