21211012222100 has 144 divisors (see below), whose sum is σ = 50881449628800. Its totient is φ = 7634064261120.

The previous prime is 21211012222093. The next prime is 21211012222111. The reversal of 21211012222100 is 122221011212.

It is a Harshad number since it is a multiple of its sum of digits (17).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 73716311 + ... + 74003489.

It is an arithmetic number, because the mean of its divisors is an integer number (353343400200).

Almost surely, 2^{21211012222100} is an apocalyptic number.

21211012222100 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 21211012222100, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (25440724814400).

21211012222100 is an abundant number, since it is smaller than the sum of its proper divisors (29670437406700).

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

21211012222100 is a wasteful number, since it uses less digits than its factorization.

21211012222100 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 289122 (or 289115 counting only the distinct ones).

The product of its (nonzero) digits is 64, while the sum is 17.

Adding to 21211012222100 its reverse (122221011212), we get a palindrome (21333233233312).

The spelling of 21211012222100 in words is "twenty-one trillion, two hundred eleven billion, twelve million, two hundred twenty-two thousand, one hundred".