28520239680 has 84 divisors (see below), whose sum is σ = 98097750972. Its totient is φ = 7605396480.

The previous prime is 28520239667. The next prime is 28520239681. The reversal of 28520239680 is 8693202582.

It is a happy number.

28520239680 is a `hidden beast` number, since 28 + 520 + 23 + 9 + 6 + 80 = 666.

It can be written as a sum of positive squares in 2 ways, for example, as 5868785664 + 22651454016 = 76608^2 + 150504^2 .

It is a hoax number, since the sum of its digits (45) coincides with the sum of the digits of its distinct prime factors.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is not an unprimeable number, because it can be changed into a prime (28520239681) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 4948551 + ... + 4954310.

Almost surely, 2^28520239680 is an apocalyptic number.

28520239680 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

28520239680 is an abundant number, since it is smaller than the sum of its proper divisors (69577511292).

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

28520239680 is a wasteful number, since it uses less digits than its factorization.

28520239680 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9902884 (or 9902871 counting only the distinct ones).

The product of its (nonzero) digits is 414720, while the sum is 45.

The spelling of 28520239680 in words is "twenty-eight billion, five hundred twenty million, two hundred thirty-nine thousand, six hundred eighty".