28131259878 has 64 divisors (see below), whose sum is σ = 64101649920. Its totient is φ = 9139840416.

The previous prime is 28131259867. The next prime is 28131259889. The reversal of 28131259878 is 87895213182.

28131259878 is a `hidden beast` number, since 28 + 13 + 12 + 598 + 7 + 8 = 666.

It is an interprime number because it is at equal distance from previous prime (28131259867) and next prime (28131259889).

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

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 1118376 + ... + 1143252.

It is an arithmetic number, because the mean of its divisors is an integer number (1001588280).

Almost surely, 2^28131259878 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 28131259878, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (32050824960).

28131259878 is an abundant number, since it is smaller than the sum of its proper divisors (35970390042).

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

28131259878 is a wasteful number, since it uses less digits than its factorization.

28131259878 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 25418 (or 25412 counting only the distinct ones).

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

The spelling of 28131259878 in words is "twenty-eight billion, one hundred thirty-one million, two hundred fifty-nine thousand, eight hundred seventy-eight".