202101202100021 has 4 divisors (see below), whose sum is σ = 230972802400032. Its totient is φ = 173229601800012.

The previous prime is 202101202099967. The next prime is 202101202100023. The reversal of 202101202100021 is 120001202101202.

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 202101202100021 - 2⁶ = 202101202099957 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 202101202099969 and 202101202100005.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (202101202100023) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (29) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 14435800149995 + ... + 14435800150008.

It is an arithmetic number, because the mean of its divisors is an integer number (57743200600008).

Almost surely, 2^{202101202100021} is an apocalyptic number.

It is an amenable number.

202101202100021 is a deficient number, since it is larger than the sum of its proper divisors (28871600300011).

202101202100021 is an equidigital number, since it uses as much as digits as its factorization.

202101202100021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 28871600300010.

The product of its (nonzero) digits is 32, while the sum is 14.

Adding to 202101202100021 its reverse (120001202101202), we get a palindrome (322102404201223).

The spelling of 202101202100021 in words is "two hundred two trillion, one hundred one billion, two hundred two million, one hundred thousand, twenty-one".