28315824637 has 4 divisors (see below), whose sum is σ = 28633980060. Its totient is φ = 27997669216.

The previous prime is 28315824619. The next prime is 28315824671. The reversal of 28315824637 is 73642851382.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 73642851382 = 2 ⋅36821425691.

It can be written as a sum of positive squares in 2 ways, for example, as 17937512761 + 10378311876 = 133931^2 + 101874^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-28315824637 is a prime.

It is a Smith number, since the sum of its digits (49) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28315824617) 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, 159077578 + ... + 159077755.

It is an arithmetic number, because the mean of its divisors is an integer number (7158495015).

Almost surely, 2^28315824637 is an apocalyptic number.

It is an amenable number.

28315824637 is a deficient number, since it is larger than the sum of its proper divisors (318155423).

28315824637 is an equidigital number, since it uses as much as digits as its factorization.

28315824637 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 318155422.

The product of its digits is 1935360, while the sum is 49.

The spelling of 28315824637 in words is "twenty-eight billion, three hundred fifteen million, eight hundred twenty-four thousand, six hundred thirty-seven".