28564718121 has 45 divisors (see below), whose sum is σ = 43361083623. Its totient is φ = 18739939680.

The previous prime is 28564718113. The next prime is 28564718131. The reversal of 28564718121 is 12181746582.

The square root of 28564718121 is 169011.

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

28564718121 is a `hidden beast` number, since 2 + 8 + 56 + 471 + 8 + 121 = 666.

It can be written as a sum of positive squares in only one way, i.e., 5485031721 + 23079686400 = 74061^2 + 151920^2 .

It is not a de Polignac number, because 28564718121 - 2³ = 28564718113 is a prime.

It is not an unprimeable number, because it can be changed into a prime (28564718131) by changing a digit.

It is a polite number, since it can be written in 44 ways as a sum of consecutive naturals, for example, 135377706 + ... + 135377916.

Almost surely, 2^28564718121 is an apocalyptic number.

28564718121 is the 169011-st square number.

28564718121 is the 84506-th centered octagonal number.

It is an amenable number.

28564718121 is a deficient number, since it is larger than the sum of its proper divisors (14796365502).

28564718121 is an frugal number, since it uses more digits than its factorization.

28564718121 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 612 (or 303 counting only the distinct ones).

The product of its digits is 215040, while the sum is 45.

The spelling of 28564718121 in words is "twenty-eight billion, five hundred sixty-four million, seven hundred eighteen thousand, one hundred twenty-one".