21222562500 has 252 divisors, whose sum is σ = 69422158260. Its totient is φ = 5460000000.

The previous prime is 21222562477. The next prime is 21222562511. The reversal of 21222562500 is 526522212.

21222562500 is a `hidden beast` number, since 2 + 12 + 2 + 25 + 625 + 0 + 0 = 666.

It can be written as a sum of positive squares in 14 ways, for example, as 10585940544 + 10636621956 = 102888^2 + 103134^2 .

It is an unprimeable number.

It is a polite number, since it can be written in 83 ways as a sum of consecutive naturals, for example, 16311850 + ... + 16313150.

It is an arithmetic number, because the mean of its divisors is an integer number (275484755).

Almost surely, 2^21222562500 is an apocalyptic number.

21222562500 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 21222562500, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (34711079130).

21222562500 is an abundant number, since it is smaller than the sum of its proper divisors (48199595760).

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

21222562500 is a wasteful number, since it uses less digits than its factorization.

21222562500 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1370 (or 1340 counting only the distinct ones).

The product of its (nonzero) digits is 4800, while the sum is 27.

The spelling of 21222562500 in words is "twenty-one billion, two hundred twenty-two million, five hundred sixty-two thousand, five hundred".