202120020100021 has 4 divisors (see below), whose sum is σ = 202426727263200. Its totient is φ = 201813312936844.

The previous prime is 202120020100001. The next prime is 202120020100027. The reversal of 202120020100021 is 120001020021202.

It is a happy number.

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-202120020100021 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 202120020099974 and 202120020100010.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (202120020100027) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 153353580601 + ... + 153353581918.

It is an arithmetic number, because the mean of its divisors is an integer number (50606681815800).

Almost surely, 2^{202120020100021} is an apocalyptic number.

It is an amenable number.

202120020100021 is a deficient number, since it is larger than the sum of its proper divisors (306707163179).

202120020100021 is an equidigital number, since it uses as much as digits as its factorization.

202120020100021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 306707163178.

The product of its (nonzero) digits is 32, while the sum is 13.

Adding to 202120020100021 its reverse (120001020021202), we get a palindrome (322121040121223).

The spelling of 202120020100021 in words is "two hundred two trillion, one hundred twenty billion, twenty million, one hundred thousand, twenty-one".