28239711864 has 128 divisors (see below), whose sum is σ = 88082211840. Its totient is φ = 7345769472.

The previous prime is 28239711833. The next prime is 28239711869. The reversal of 28239711864 is 46811793282.

It is a happy number.

It is a hoax number, since the sum of its digits (51) coincides with the sum of the digits of its distinct prime factors.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28239711869) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 70869 + ... + 247995.

It is an arithmetic number, because the mean of its divisors is an integer number (688142280).

Almost surely, 2^28239711864 is an apocalyptic number.

28239711864 is a gapful number since it is divisible by the number (24) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 28239711864, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (44041105920).

28239711864 is an abundant number, since it is smaller than the sum of its proper divisors (59842499976).

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

28239711864 is a wasteful number, since it uses less digits than its factorization.

28239711864 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 177229 (or 177225 counting only the distinct ones).

The product of its digits is 1161216, while the sum is 51.

The spelling of 28239711864 in words is "twenty-eight billion, two hundred thirty-nine million, seven hundred eleven thousand, eight hundred sixty-four".