28752811621 has 4 divisors (see below), whose sum is σ = 28943227744. Its totient is φ = 28562395500.

The previous prime is 28752811609. The next prime is 28752811631. The reversal of 28752811621 is 12611825782.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 28752811621 - 2¹⁷ = 28752680549 is a prime.

It is a super-2 number, since 2×28752811621² (a number of 22 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28752811601) 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, 95207835 + ... + 95208136.

It is an arithmetic number, because the mean of its divisors is an integer number (7235806936).

Almost surely, 2^28752811621 is an apocalyptic number.

It is an amenable number.

28752811621 is a deficient number, since it is larger than the sum of its proper divisors (190416123).

28752811621 is a wasteful number, since it uses less digits than its factorization.

28752811621 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 190416122.

The product of its digits is 107520, while the sum is 43.

The spelling of 28752811621 in words is "twenty-eight billion, seven hundred fifty-two million, eight hundred eleven thousand, six hundred twenty-one".