21222100000 has 144 divisors (see below), whose sum is σ = 54499386816. Its totient is φ = 8118880000.

The previous prime is 21222099973. The next prime is 21222100087. The reversal of 21222100000 is 122212.

It is a Harshad number since it is a multiple of its sum of digits (10).

It is a self number, because there is not a number n which added to its sum of digits gives 21222100000.

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, 2295387 + ... + 2304613.

It is an arithmetic number, because the mean of its divisors is an integer number (378467964).

Almost surely, 2^21222100000 is an apocalyptic number.

21222100000 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 21222100000, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (27249693408).

21222100000 is an abundant number, since it is smaller than the sum of its proper divisors (33277286816).

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

21222100000 is an frugal number, since it uses more digits than its factorization.

21222100000 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9285 (or 9257 counting only the distinct ones).

The product of its (nonzero) digits is 16, while the sum is 10.

Adding to 21222100000 its reverse (122212), we get a palindrome (21222222212).

The spelling of 21222100000 in words is "twenty-one billion, two hundred twenty-two million, one hundred thousand".