21112655872 has 312 divisors, whose sum is σ = 54726626592. Its totient is φ = 8051097600.

The previous prime is 21112655869. The next prime is 21112655933. The reversal of 21112655872 is 27855621112.

Its product of digits (67200) is a multiple of the sum of its prime divisors (224).

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 161165247 + ... + 161165377.

Almost surely, 2^21112655872 is an apocalyptic number.

21112655872 is a gapful number since it is divisible by the number (22) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21112655872, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (27363313296).

21112655872 is an abundant number, since it is smaller than the sum of its proper divisors (33613970720).

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

21112655872 is a wasteful number, since it uses less digits than its factorization.

21112655872 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 253 (or 224 counting only the distinct ones).

The product of its digits is 67200, while the sum is 40.

The spelling of 21112655872 in words is "twenty-one billion, one hundred twelve million, six hundred fifty-five thousand, eight hundred seventy-two".