21211220000 has 120 divisors (see below), whose sum is σ = 54930229200. Its totient is φ = 8037792000.

The previous prime is 21211219973. The next prime is 21211220021. The reversal of 21211220000 is 2211212.

It is a happy number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 19 ways as a sum of consecutive naturals, for example, 352091 + ... + 407909.

It is an arithmetic number, because the mean of its divisors is an integer number (457751910).

Almost surely, 2^21211220000 is an apocalyptic number.

21211220000 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 21211220000, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (27465114600).

21211220000 is an abundant number, since it is smaller than the sum of its proper divisors (33719009200).

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

21211220000 is an equidigital number, since it uses as much as digits as its factorization.

21211220000 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 55868 (or 55845 counting only the distinct ones).

The product of its (nonzero) digits is 16, while the sum is 11.

Adding to 21211220000 its reverse (2211212), we get a palindrome (21213431212).

The spelling of 21211220000 in words is "twenty-one billion, two hundred eleven million, two hundred twenty thousand".