28706863761 has 9 divisors (see below), whose sum is σ = 41466204091. Its totient is φ = 19137570312.

The previous prime is 28706863741. The next prime is 28706863777. The reversal of 28706863761 is 16736860782.

The square root of 28706863761 is 169431.

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., 736308225 + 27970555536 = 27135^2 + 167244^2 .

It is a tau number, because it is divible by the number of its divisors (9).

It is not a de Polignac number, because 28706863761 - 2²¹ = 28704766609 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 28706863698 and 28706863707.

It is not an unprimeable number, because it can be changed into a prime (28706863711) 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, 480055 + ... + 536531.

Almost surely, 2^28706863761 is an apocalyptic number.

28706863761 is the 169431-st square number.

28706863761 is the 84716-th centered octagonal number.

It is an amenable number.

28706863761 is a deficient number, since it is larger than the sum of its proper divisors (12759340330).

28706863761 is an frugal number, since it uses more digits than its factorization.

28706863761 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 112960 (or 56480 counting only the distinct ones).

The product of its (nonzero) digits is 4064256, while the sum is 54.

The spelling of 28706863761 in words is "twenty-eight billion, seven hundred six million, eight hundred sixty-three thousand, seven hundred sixty-one".