21000012011999 has 2 divisors, whose sum is σ = 21000012012000. Its totient is φ = 21000012011998.

The previous prime is 21000012011947. The next prime is 21000012012037. The reversal of 21000012011999 is 99911021000012.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 21000012011999 - 2⁴⁴ = 3407825967583 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21000012011399) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10500006005999 + 10500006006000.

It is an arithmetic number, because the mean of its divisors is an integer number (10500006006000).

Almost surely, 2^{21000012011999} is an apocalyptic number.

21000012011999 is a deficient number, since it is larger than the sum of its proper divisors (1).

21000012011999 is an equidigital number, since it uses as much as digits as its factorization.

21000012011999 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 2916, while the sum is 35.

The spelling of 21000012011999 in words is "twenty-one trillion, twelve million, eleven thousand, nine hundred ninety-nine".