28725165225 has 27 divisors (see below), whose sum is σ = 51454516503. Its totient is φ = 15318732240.

The previous prime is 28725165211. The next prime is 28725165239. The reversal of 28725165225 is 52256152782.

The square root of 28725165225 is 169485.

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

28725165225 is a `hidden beast` number, since 2 + 8 + 72 + 51 + 6 + 522 + 5 = 666.

It is an interprime number because it is at equal distance from previous prime (28725165211) and next prime (28725165239).

It can be written as a sum of positive squares in only one way, i.e., 10341059481 + 18384105744 = 101691^2 + 135588^2 .

It is not a de Polignac number, because 28725165225 - 2²⁵ = 28691610793 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is an unprimeable number.

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 26 ways as a sum of consecutive naturals, for example, 2536626 + ... + 2547924.

Almost surely, 2^28725165225 is an apocalyptic number.

28725165225 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

28725165225 is the 169485-th square number.

28725165225 is the 84743-rd centered octagonal number.

It is an amenable number.

28725165225 is a deficient number, since it is larger than the sum of its proper divisors (22729351278).

28725165225 is an frugal number, since it uses more digits than its factorization.

28725165225 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 22614 (or 11307 counting only the distinct ones).

The product of its digits is 672000, while the sum is 45.

The spelling of 28725165225 in words is "twenty-eight billion, seven hundred twenty-five million, one hundred sixty-five thousand, two hundred twenty-five".