28133688361 has 9 divisors (see below), whose sum is σ = 28843662679. Its totient is φ = 27440791600.

The previous prime is 28133688353. The next prime is 28133688371. The reversal of 28133688361 is 16388633182.

The square root of 28133688361 is 167731.

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., 1355638761 + 26778049600 = 36819^2 + 163640^2 .

It is not a de Polignac number, because 28133688361 - 2³ = 28133688353 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (28133688371) by changing a digit.

It is a polite number, since it can be written in 8 ways as a sum of consecutive naturals, for example, 6874926 + ... + 6879016.

Almost surely, 2^28133688361 is an apocalyptic number.

28133688361 is the 167731-st square number.

28133688361 is the 83866-th centered octagonal number.

It is an amenable number.

28133688361 is a deficient number, since it is larger than the sum of its proper divisors (709974318).

28133688361 is an frugal number, since it uses more digits than its factorization.

28133688361 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8264 (or 4132 counting only the distinct ones).

The product of its digits is 995328, while the sum is 49.

Multiplying 28133688361 by its sum of digits (49), we get a square (1378550729689 = 1174117²).

The spelling of 28133688361 in words is "twenty-eight billion, one hundred thirty-three million, six hundred eighty-eight thousand, three hundred sixty-one".