21012102020101 has 4 divisors (see below), whose sum is σ = 21013591514752. Its totient is φ = 21010612525452.

The previous prime is 21012102020089. The next prime is 21012102020191. The reversal of 21012102020101 is 10102020121012.

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 not a de Polignac number, because 21012102020101 - 2¹¹ = 21012102018053 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 (21012102020191) 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, 744726165 + ... + 744754378.

It is an arithmetic number, because the mean of its divisors is an integer number (5253397878688).

Almost surely, 2^{21012102020101} is an apocalyptic number.

It is an amenable number.

21012102020101 is a deficient number, since it is larger than the sum of its proper divisors (1489494651).

21012102020101 is a wasteful number, since it uses less digits than its factorization.

21012102020101 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1489494650.

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

Adding to 21012102020101 its reverse (10102020121012), we get a palindrome (31114122141113).

The spelling of 21012102020101 in words is "twenty-one trillion, twelve billion, one hundred two million, twenty thousand, one hundred one".