28751821893 has 6 divisors (see below), whose sum is σ = 41530409414. Its totient is φ = 19167881256.

The previous prime is 28751821871. The next prime is 28751821939. The reversal of 28751821893 is 39812815782.

28751821893 is a `hidden beast` number, since 28 + 7 + 518 + 2 + 18 + 93 = 666.

It can be written as a sum of positive squares in only one way, i.e., 25636172769 + 3115649124 = 160113^2 + 55818^2 .

It is not a de Polignac number, because 28751821893 - 2⁹ = 28751821381 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28751821093) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 1597323430 + ... + 1597323447.

Almost surely, 2^28751821893 is an apocalyptic number.

It is an amenable number.

28751821893 is a deficient number, since it is larger than the sum of its proper divisors (12778587521).

28751821893 is a wasteful number, since it uses less digits than its factorization.

28751821893 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3194646883 (or 3194646880 counting only the distinct ones).

The product of its digits is 1935360, while the sum is 54.

The spelling of 28751821893 in words is "twenty-eight billion, seven hundred fifty-one million, eight hundred twenty-one thousand, eight hundred ninety-three".