28111552225 has 9 divisors (see below), whose sum is σ = 34859364313. Its totient is φ = 22488571120.

The previous prime is 28111552213. The next prime is 28111552243. The reversal of 28111552225 is 52225511182.

The square root of 28111552225 is 167665.

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

It can be written as a sum of positive squares in 4 ways, for example, as 799362529 + 27312189696 = 28273^2 + 165264^2 .

It is not a de Polignac number, because 28111552225 - 2⁷ = 28111552097 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, 821559 + ... + 855091.

Almost surely, 2^28111552225 is an apocalyptic number.

28111552225 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

28111552225 is the 167665-th square number.

28111552225 is the 83833-rd centered octagonal number.

It is an amenable number.

28111552225 is a deficient number, since it is larger than the sum of its proper divisors (6747812088).

28111552225 is an frugal number, since it uses more digits than its factorization.

28111552225 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 67076 (or 33538 counting only the distinct ones).

The product of its digits is 16000, while the sum is 34.

The spelling of 28111552225 in words is "twenty-eight billion, one hundred eleven million, five hundred fifty-two thousand, two hundred twenty-five".