21547142256 has 80 divisors (see below), whose sum is σ = 58153777920. Its totient is φ = 6861803520.

The previous prime is 21547142237. The next prime is 21547142263. The reversal of 21547142256 is 65224174512.

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, 936976 + ... + 959696.

It is an arithmetic number, because the mean of its divisors is an integer number (726922224).

Almost surely, 2^21547142256 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21547142256, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (29076888960).

21547142256 is an abundant number, since it is smaller than the sum of its proper divisors (36606635664).

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

21547142256 is a wasteful number, since it uses less digits than its factorization.

21547142256 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 23614 (or 23608 counting only the distinct ones).

The product of its digits is 134400, while the sum is 39.

The spelling of 21547142256 in words is "twenty-one billion, five hundred forty-seven million, one hundred forty-two thousand, two hundred fifty-six".