166084776225 has 81 divisors (see below), whose sum is σ = 301571828779. Its totient is φ = 87375504000.

The previous prime is 166084776191. The next prime is 166084776229. The reversal of 166084776225 is 522677480661.

It is a happy number.

The square root of 166084776225 is 407535.

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

166084776225 is a `hidden beast` number, since 1 + 6 + 6 + 0 + 8 + 4 + 7 + 7 + 622 + 5 = 666.

It can be written as a sum of positive squares in 13 ways, for example, as 96572399121 + 69512377104 = 310761^2 + 263652^2 .

It is not a de Polignac number, because 166084776225 - 2³¹ = 163937292577 is a prime.

It is a Smith number, since the sum of its digits (54) coincides with the sum of the digits of its prime factors.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (166084776229) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 80 ways as a sum of consecutive naturals, for example, 617415391 + ... + 617415659.

Almost surely, 2^166084776225 is an apocalyptic number.

166084776225 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

166084776225 is the 407535-th square number.

166084776225 is the 203768-th centered octagonal number.

It is an amenable number.

166084776225 is a deficient number, since it is larger than the sum of its proper divisors (135487052554).

166084776225 is an equidigital number, since it uses as much as digits as its factorization.

166084776225 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 756 (or 378 counting only the distinct ones).

The product of its (nonzero) digits is 6773760, while the sum is 54.

The spelling of 166084776225 in words is "one hundred sixty-six billion, eighty-four million, seven hundred seventy-six thousand, two hundred twenty-five".