28721956160 has 56 divisors (see below), whose sum is σ = 68813879136. Its totient is φ = 11418278400.

The previous prime is 28721956121. The next prime is 28721956181. The reversal of 28721956160 is 6165912782.

It is a happy number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 223166 + ... + 327485.

Almost surely, 2^28721956160 is an apocalyptic number.

28721956160 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

28721956160 is an abundant number, since it is smaller than the sum of its proper divisors (40091922976).

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

28721956160 is a wasteful number, since it uses less digits than its factorization.

28721956160 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 550831 (or 550821 counting only the distinct ones).

The product of its (nonzero) digits is 362880, while the sum is 47.

The spelling of 28721956160 in words is "twenty-eight billion, seven hundred twenty-one million, nine hundred fifty-six thousand, one hundred sixty".