28765177609 has 9 divisors (see below), whose sum is σ = 33462914247. Its totient is φ = 24654848904.

The previous prime is 28765177591. The next prime is 28765177643. The reversal of 28765177609 is 90677156782.

The square root of 28765177609 is 169603.

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., 3158777209 + 25606400400 = 56203^2 + 160020^2 .

It is not a de Polignac number, because 28765177609 - 2¹⁵ = 28765144841 is a prime.

It is not an unprimeable number, because it can be changed into a prime (28765177669) 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, 1175107 + ... + 1199335.

It is an arithmetic number, because the mean of its divisors is an integer number (3718101583).

Almost surely, 2^28765177609 is an apocalyptic number.

28765177609 is the 169603-rd square number.

28765177609 is the 84802-nd centered octagonal number.

It is an amenable number.

28765177609 is a deficient number, since it is larger than the sum of its proper divisors (4697736638).

28765177609 is an frugal number, since it uses more digits than its factorization.

28765177609 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 48472 (or 24236 counting only the distinct ones).

The product of its (nonzero) digits is 8890560, while the sum is 58.

The spelling of 28765177609 in words is "twenty-eight billion, seven hundred sixty-five million, one hundred seventy-seven thousand, six hundred nine".