21000202002161 has 2 divisors, whose sum is σ = 21000202002162. Its totient is φ = 21000202002160.

The previous prime is 21000202002139. The next prime is 21000202002167. The reversal of 21000202002161 is 16120020200012.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 18882987847936 + 2117214154225 = 4345456^2 + 1455065^2 .

It is a cyclic number.

It is not a de Polignac number, because 21000202002161 - 2³⁰ = 20999128260337 is a prime.

It is not a weakly prime, because it can be changed into another prime (21000202002167) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10500101001080 + 10500101001081.

It is an arithmetic number, because the mean of its divisors is an integer number (10500101001081).

Almost surely, 2^{21000202002161} is an apocalyptic number.

It is an amenable number.

21000202002161 is a deficient number, since it is larger than the sum of its proper divisors (1).

21000202002161 is an equidigital number, since it uses as much as digits as its factorization.

21000202002161 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 96, while the sum is 17.

Adding to 21000202002161 its reverse (16120020200012), we get a palindrome (37120222202173).

The spelling of 21000202002161 in words is "twenty-one trillion, two hundred two million, two thousand, one hundred sixty-one".