202012200100021 has 4 divisors (see below), whose sum is σ = 202035665342700. Its totient is φ = 201988734857344.

The previous prime is 202012200099977. The next prime is 202012200100027. The reversal of 202012200100021 is 120001002210202.

It is a happy number.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 38253111708100 + 163759088391921 = 6184910^2 + 12796839^2 .

It is a cyclic number.

It is not a de Polignac number, because 202012200100021 - 2⁹ = 202012200099509 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 202012200099974 and 202012200100010.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (202012200100027) 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, 11732608426 + ... + 11732625643.

It is an arithmetic number, because the mean of its divisors is an integer number (50508916335675).

Almost surely, 2^{202012200100021} is an apocalyptic number.

It is an amenable number.

202012200100021 is a deficient number, since it is larger than the sum of its proper divisors (23465242679).

202012200100021 is an equidigital number, since it uses as much as digits as its factorization.

202012200100021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 23465242678.

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

Adding to 202012200100021 its reverse (120001002210202), we get a palindrome (322013202310223).

The spelling of 202012200100021 in words is "two hundred two trillion, twelve billion, two hundred million, one hundred thousand, twenty-one".