28539781297920 has 144 divisors (see below), whose sum is σ = 101276585145120. Its totient is φ = 7610608336896.

The previous prime is 28539781297901. The next prime is 28539781297949. The reversal of 28539781297920 is 2979218793582.

28539781297920 is a `hidden beast` number, since 2 + 8 + 539 + 7 + 8 + 12 + 9 + 79 + 2 + 0 = 666.

It is a tau number, because it is divible by the number of its divisors (144).

It is a Harshad number since it is a multiple of its sum of digits (72).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 412867369 + ... + 412936488.

Almost surely, 2^{28539781297920} is an apocalyptic number.

28539781297920 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

28539781297920 is an abundant number, since it is smaller than the sum of its proper divisors (72736803847200).

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

28539781297920 is an equidigital number, since it uses as much as digits as its factorization.

28539781297920 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 825803887 (or 825803867 counting only the distinct ones).

The product of its (nonzero) digits is 274337280, while the sum is 72.

The spelling of 28539781297920 in words is "twenty-eight trillion, five hundred thirty-nine billion, seven hundred eighty-one million, two hundred ninety-seven thousand, nine hundred twenty".