21012100012100 has 18 divisors (see below), whose sum is σ = 45596257026474. Its totient is φ = 8404840004800.

The previous prime is 21012100012067. The next prime is 21012100012121. The reversal of 21012100012100 is 121000121012.

It can be written as a sum of positive squares in 3 ways, for example, as 4044571476544 + 16967528535556 = 2011112^2 + 4119166^2 .

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 105060499961 + ... + 105060500160.

Almost surely, 2^{21012100012100} is an apocalyptic number.

21012100012100 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21012100012100 is an abundant number, since it is smaller than the sum of its proper divisors (24584157014374).

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

21012100012100 is a wasteful number, since it uses less digits than its factorization.

21012100012100 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 210121000135 (or 210121000128 counting only the distinct ones).

The product of its (nonzero) digits is 8, while the sum is 11.

Adding to 21012100012100 its reverse (121000121012), we get a palindrome (21133100133112).

The spelling of 21012100012100 in words is "twenty-one trillion, twelve billion, one hundred million, twelve thousand, one hundred".