21000209999599 has 2 divisors, whose sum is σ = 21000209999600. Its totient is φ = 21000209999598.

The previous prime is 21000209999597. The next prime is 21000209999693. The reversal of 21000209999599 is 99599990200012.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 21000209999599 - 2¹ = 21000209999597 is a prime.

Together with 21000209999597, it forms a pair of twin primes.

It is a self number, because there is not a number n which added to its sum of digits gives 21000209999599.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21000209999591) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10500104999799 + 10500104999800.

It is an arithmetic number, because the mean of its divisors is an integer number (10500104999800).

Almost surely, 2^{21000209999599} is an apocalyptic number.

21000209999599 is a deficient number, since it is larger than the sum of its proper divisors (1).

21000209999599 is an equidigital number, since it uses as much as digits as its factorization.

21000209999599 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 10628820, while the sum is 64.

The spelling of 21000209999599 in words is "twenty-one trillion, two hundred nine million, nine hundred ninety-nine thousand, five hundred ninety-nine".