21001221221110 has 96 divisors (see below), whose sum is σ = 43417074539520. Its totient is φ = 7290097027200.

The previous prime is 21001221221041. The next prime is 21001221221147. The reversal of 21001221221110 is 1112212210012.

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, 1710075 + ... + 6702745.

It is an arithmetic number, because the mean of its divisors is an integer number (452261193120).

Almost surely, 2^{21001221221110} is an apocalyptic number.

21001221221110 is an abundant number, since it is smaller than the sum of its proper divisors (22415853318410).

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

21001221221110 is a wasteful number, since it uses less digits than its factorization.

21001221221110 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4992854 (or 4992841 counting only the distinct ones).

The product of its (nonzero) digits is 32, while the sum is 16.

Adding to 21001221221110 its reverse (1112212210012), we get a palindrome (22113433431122).

The spelling of 21001221221110 in words is "twenty-one trillion, one billion, two hundred twenty-one million, two hundred twenty-one thousand, one hundred ten".