28716508657 has 12 divisors (see below), whose sum is σ = 29496338508. Its totient is φ = 27954201600.

The previous prime is 28716508643. The next prime is 28716508687. The reversal of 28716508657 is 75680561782.

It can be written as a sum of positive squares in 6 ways, for example, as 15435329121 + 13281179536 = 124239^2 + 115244^2 .

It is not a de Polignac number, because 28716508657 - 2⁷ = 28716508529 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 28716508598 and 28716508607.

It is not an unprimeable number, because it can be changed into a prime (28716508627) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 321157 + ... + 400717.

It is an arithmetic number, because the mean of its divisors is an integer number (2458028209).

Almost surely, 2^28716508657 is an apocalyptic number.

It is an amenable number.

28716508657 is a deficient number, since it is larger than the sum of its proper divisors (779829851).

28716508657 is an frugal number, since it uses more digits than its factorization.

28716508657 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 79780 (or 79719 counting only the distinct ones).

The product of its (nonzero) digits is 5644800, while the sum is 55.

The spelling of 28716508657 in words is "twenty-eight billion, seven hundred sixteen million, five hundred eight thousand, six hundred fifty-seven".