21012100202101 has 4 divisors (see below), whose sum is σ = 21012553808992. Its totient is φ = 21011646595212.

The previous prime is 21012100202089. The next prime is 21012100202167. The reversal of 21012100202101 is 10120200121012.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21012100202101 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21012100202201) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 226733955 + ... + 226826608.

It is an arithmetic number, because the mean of its divisors is an integer number (5253138452248).

Almost surely, 2^{21012100202101} is an apocalyptic number.

It is an amenable number.

21012100202101 is a deficient number, since it is larger than the sum of its proper divisors (453606891).

21012100202101 is an equidigital number, since it uses as much as digits as its factorization.

21012100202101 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 453606890.

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

Adding to 21012100202101 its reverse (10120200121012), we get a palindrome (31132300323113).

The spelling of 21012100202101 in words is "twenty-one trillion, twelve billion, one hundred million, two hundred two thousand, one hundred one".