21551255200 has 144 divisors (see below), whose sum is σ = 53389082880. Its totient is φ = 8494110720.

The previous prime is 21551255179. The next prime is 21551255239. The reversal of 21551255200 is 255215512.

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, 19088236 + ... + 19089364.

It is an arithmetic number, because the mean of its divisors is an integer number (370757520).

Almost surely, 2^21551255200 is an apocalyptic number.

21551255200 is a gapful number since it is divisible by the number (20) 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 21551255200, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (26694541440).

21551255200 is an abundant number, since it is smaller than the sum of its proper divisors (31837827680).

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

21551255200 is a wasteful number, since it uses less digits than its factorization.

21551255200 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1479 (or 1466 counting only the distinct ones).

The product of its (nonzero) digits is 5000, while the sum is 28.

The spelling of 21551255200 in words is "twenty-one billion, five hundred fifty-one million, two hundred fifty-five thousand, two hundred".