28239711858 has 78 divisors (see below), whose sum is σ = 63931515039. Its totient is φ = 9355487364.

The previous prime is 28239711833. The next prime is 28239711869. The reversal of 28239711858 is 85811793282.

It can be written as a sum of positive squares in only one way, i.e., 14119855929 + 14119855929 = 118827^2 + 118827^2 .

It is an ABA number since it can be written as A⋅B^A, here for A=2, B=118827.

It is a Harshad number since it is a multiple of its sum of digits (54).

Its product of digits (1935360) is a multiple of the sum of its prime divisors (168).

It is an unprimeable number.

It is a polite number, since it can be written in 38 ways as a sum of consecutive naturals, for example, 173249685 + ... + 173249847.

Almost surely, 2^28239711858 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 28239711858

28239711858 is an abundant number, since it is smaller than the sum of its proper divisors (35691803181).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

28239711858 is an frugal number, since it uses more digits than its factorization.

28239711858 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 364 (or 168 counting only the distinct ones).

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

The spelling of 28239711858 in words is "twenty-eight billion, two hundred thirty-nine million, seven hundred eleven thousand, eight hundred fifty-eight".