28357543657 has 16 divisors (see below), whose sum is σ = 29449054800. Its totient is φ = 27273818880.

The previous prime is 28357543649. The next prime is 28357543691. The reversal of 28357543657 is 75634575382.

It can be written as a sum of positive squares in 8 ways, for example, as 543309481 + 27814234176 = 23309^2 + 166776^2 .

It is a cyclic number.

It is not a de Polignac number, because 28357543657 - 2³ = 28357543649 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 28357543598 and 28357543607.

It is not an unprimeable number, because it can be changed into a prime (28307543657) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 12766807 + ... + 12769027.

It is an arithmetic number, because the mean of its divisors is an integer number (1840565925).

Almost surely, 2^28357543657 is an apocalyptic number.

It is an amenable number.

28357543657 is a deficient number, since it is larger than the sum of its proper divisors (1091511143).

28357543657 is a wasteful number, since it uses less digits than its factorization.

28357543657 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3756.

The product of its digits is 21168000, while the sum is 55.

The spelling of 28357543657 in words is "twenty-eight billion, three hundred fifty-seven million, five hundred forty-three thousand, six hundred fifty-seven".