21020210201999 has 2 divisors, whose sum is σ = 21020210202000. Its totient is φ = 21020210201998.

The previous prime is 21020210201993. The next prime is 21020210202059. The reversal of 21020210201999 is 99910201202012.

It is a happy number.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 21020210201999 - 2⁴⁰ = 19920698574223 is a prime.

It is a Sophie Germain prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21020210201993) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10510105100999 + 10510105101000.

It is an arithmetic number, because the mean of its divisors is an integer number (10510105101000).

Almost surely, 2^{21020210201999} is an apocalyptic number.

21020210201999 is a deficient number, since it is larger than the sum of its proper divisors (1).

21020210201999 is an equidigital number, since it uses as much as digits as its factorization.

21020210201999 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 11664, while the sum is 38.

The spelling of 21020210201999 in words is "twenty-one trillion, twenty billion, two hundred ten million, two hundred one thousand, nine hundred ninety-nine".