21210100212100 has 36 divisors (see below), whose sum is σ = 46280204336548. Its totient is φ = 8437166928000.

The previous prime is 21210100212073. The next prime is 21210100212107. The reversal of 21210100212100 is 121200101212.

It can be written as a sum of positive squares in 6 ways, for example, as 4764415024516 + 16445685187584 = 2182754^2 + 4055328^2 .

It is not an unprimeable number, because it can be changed into a prime (21210100212107) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 585896271 + ... + 585932470.

Almost surely, 2^{21210100212100} is an apocalyptic number.

21210100212100 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21210100212100 is an abundant number, since it is smaller than the sum of its proper divisors (25070104124448).

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

21210100212100 is a wasteful number, since it uses less digits than its factorization.

21210100212100 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1171828936 (or 1171828929 counting only the distinct ones).

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

Adding to 21210100212100 its reverse (121200101212), we get a palindrome (21331300313312).

The spelling of 21210100212100 in words is "twenty-one trillion, two hundred ten billion, one hundred million, two hundred twelve thousand, one hundred".