28828637657 has 4 divisors (see below), whose sum is σ = 28830447780. Its totient is φ = 28826827536.

The previous prime is 28828637633. The next prime is 28828637671. The reversal of 28828637657 is 75673682882.

It is a happy number.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 18091326016 + 10737311641 = 134504^2 + 103621^2 .

It is a cyclic number.

It is not a de Polignac number, because 28828637657 - 2⁸ = 28828637401 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 28828637657.

It is not an unprimeable number, because it can be changed into a prime (28828667657) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 880958 + ... + 913095.

It is an arithmetic number, because the mean of its divisors is an integer number (7207611945).

Almost surely, 2^28828637657 is an apocalyptic number.

It is an amenable number.

28828637657 is a deficient number, since it is larger than the sum of its proper divisors (1810123).

28828637657 is a wasteful number, since it uses less digits than its factorization.

28828637657 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1810122.

The product of its digits is 54190080, while the sum is 62.

The spelling of 28828637657 in words is "twenty-eight billion, eight hundred twenty-eight million, six hundred thirty-seven thousand, six hundred fifty-seven".