21000001122210 has 256 divisors, whose sum is σ = 55935331135488. Its totient is φ = 5003447500800.

The previous prime is 21000001122187. The next prime is 21000001122229. The reversal of 21000001122210 is 1222110000012.

It is an unprimeable number.

It is a polite number, since it can be written in 127 ways as a sum of consecutive naturals, for example, 3898271137 + ... + 3898276523.

It is an arithmetic number, because the mean of its divisors is an integer number (218497387248).

Almost surely, 2^{21000001122210} is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21000001122210, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (27967665567744).

21000001122210 is an abundant number, since it is smaller than the sum of its proper divisors (34935330013278).

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

21000001122210 is a wasteful number, since it uses less digits than its factorization.

21000001122210 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6329.

The product of its (nonzero) digits is 16, while the sum is 12.

Adding to 21000001122210 its reverse (1222110000012), we get a palindrome (22222111122222).

The spelling of 21000001122210 in words is "twenty-one trillion, one million, one hundred twenty-two thousand, two hundred ten".