90808809025 has 27 divisors (see below), whose sum is σ = 123792749283. Its totient is φ = 66030716400.

The previous prime is 90808809023. The next prime is 90808809029. The reversal of 90808809025 is 52090880809.

It is a happy number.

The square root of 90808809025 is 301345.

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., 32691171249 + 58117637776 = 180807^2 + 241076^2 .

It is not a de Polignac number, because 90808809025 - 2¹ = 90808809023 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 90808809025.

It is not an unprimeable number, because it can be changed into a prime (90808809023) by changing a digit.

It is a polite number, since it can be written in 26 ways as a sum of consecutive naturals, for example, 16571236 + ... + 16576714.

Almost surely, 2^90808809025 is an apocalyptic number.

90808809025 is the 301345-th square number.

90808809025 is the 150673-rd centered octagonal number.

It is an amenable number.

90808809025 is a deficient number, since it is larger than the sum of its proper divisors (32983940258).

90808809025 is an frugal number, since it uses more digits than its factorization.

90808809025 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10990 (or 5495 counting only the distinct ones).

The product of its (nonzero) digits is 414720, while the sum is 49.

Multiplying 90808809025 by its sum of digits (49), we get a square (4449631642225 = 2109415²).

The spelling of 90808809025 in words is "ninety billion, eight hundred eight million, eight hundred nine thousand, twenty-five".