21011002122100 has 72 divisors (see below), whose sum is σ = 48773556964440. Its totient is φ = 7828477624320.

The previous prime is 21011002122073. The next prime is 21011002122119. The reversal of 21011002122100 is 122120011012.

It can be written as a sum of positive squares in 12 ways, for example, as 8248774596624 + 12762227525476 = 2872068^2 + 3572426^2 .

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 63543415 + ... + 63873214.

It is an arithmetic number, because the mean of its divisors is an integer number (677410513395).

Almost surely, 2^{21011002122100} is an apocalyptic number.

21011002122100 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21011002122100 is an abundant number, since it is smaller than the sum of its proper divisors (27762554842340).

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

21011002122100 is a wasteful number, since it uses less digits than its factorization.

21011002122100 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 127416757 (or 127416750 counting only the distinct ones).

The product of its (nonzero) digits is 16, while the sum is 13.

Adding to 21011002122100 its reverse (122120011012), we get a palindrome (21133122133112).

The spelling of 21011002122100 in words is "twenty-one trillion, eleven billion, two million, one hundred twenty-two thousand, one hundred".