21001012199 has 2 divisors, whose sum is σ = 21001012200. Its totient is φ = 21001012198.

The previous prime is 21001012187. The next prime is 21001012243. The reversal of 21001012199 is 99121010012.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 21001012199 - 2⁴ = 21001012183 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21001012129) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10500506099 + 10500506100.

It is an arithmetic number, because the mean of its divisors is an integer number (10500506100).

Almost surely, 2^21001012199 is an apocalyptic number.

21001012199 is a deficient number, since it is larger than the sum of its proper divisors (1).

21001012199 is an equidigital number, since it uses as much as digits as its factorization.

21001012199 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 324, while the sum is 26.

The spelling of 21001012199 in words is "twenty-one billion, one million, twelve thousand, one hundred ninety-nine".