28161874225 has 9 divisors (see below), whose sum is σ = 34921764523. Its totient is φ = 22528828120.

The previous prime is 28161874171. The next prime is 28161874231. The reversal of 28161874225 is 52247816182.

The square root of 28161874225 is 167815.

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., 10138274721 + 18023599504 = 100689^2 + 134252^2 .

It is not a de Polignac number, because 28161874225 - 2¹⁵ = 28161841457 is a prime.

It is a Duffinian number.

It is an unprimeable number.

It is a polite number, since it can be written in 8 ways as a sum of consecutive naturals, for example, 822294 + ... + 855856.

Almost surely, 2^28161874225 is an apocalyptic number.

28161874225 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

28161874225 is the 167815-th square number.

28161874225 is the 83908-th centered octagonal number.

It is an amenable number.

28161874225 is a deficient number, since it is larger than the sum of its proper divisors (6759890298).

28161874225 is an frugal number, since it uses more digits than its factorization.

28161874225 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 67136 (or 33568 counting only the distinct ones).

The product of its digits is 430080, while the sum is 46.

The spelling of 28161874225 in words is "twenty-eight billion, one hundred sixty-one million, eight hundred seventy-four thousand, two hundred twenty-five".