21021222102100 has 72 divisors (see below), whose sum is σ = 49767249129696. Its totient is φ = 7643422800000.

The previous prime is 21021222102091. The next prime is 21021222102107. The reversal of 21021222102100 is 120122212012.

It is a happy number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21021222102107) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 12054495 + ... + 13687705.

It is an arithmetic number, because the mean of its divisors is an integer number (691211793468).

Almost surely, 2^{21021222102100} is an apocalyptic number.

21021222102100 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21021222102100 is an abundant number, since it is smaller than the sum of its proper divisors (28746027027596).

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

21021222102100 is a wasteful number, since it uses less digits than its factorization.

21021222102100 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1644937 (or 1644930 counting only the distinct ones).

The product of its (nonzero) digits is 64, while the sum is 16.

Adding to 21021222102100 its reverse (120122212012), we get a palindrome (21141344314112).

The spelling of 21021222102100 in words is "twenty-one trillion, twenty-one billion, two hundred twenty-two million, one hundred two thousand, one hundred".