20100101210021 has 4 divisors (see below), whose sum is σ = 22971544240032. Its totient is φ = 17228658180012.

The previous prime is 20100101210009. The next prime is 20100101210039. The reversal of 20100101210021 is 12001210100102.

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 20100101210021 - 2²⁶ = 20100034101157 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 20100101209984 and 20100101210011.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20100101210071) 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, 1435721514995 + ... + 1435721515008.

It is an arithmetic number, because the mean of its divisors is an integer number (5742886060008).

Almost surely, 2^{20100101210021} is an apocalyptic number.

It is an amenable number.

20100101210021 is a deficient number, since it is larger than the sum of its proper divisors (2871443030011).

20100101210021 is an equidigital number, since it uses as much as digits as its factorization.

20100101210021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2871443030010.

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

Adding to 20100101210021 its reverse (12001210100102), we get a palindrome (32101311310123).

The spelling of 20100101210021 in words is "twenty trillion, one hundred billion, one hundred one million, two hundred ten thousand, twenty-one".