21012003239 has 2 divisors, whose sum is σ = 21012003240. Its totient is φ = 21012003238.

The previous prime is 21012003167. The next prime is 21012003241. The reversal of 21012003239 is 93230021012.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 21012003239 - 2¹² = 21011999143 is a prime.

It is a super-2 number, since 2×21012003239² (a number of 21 digits) contains 22 as substring.

Together with 21012003241, it forms a pair of twin primes.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21012003269) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10506001619 + 10506001620.

It is an arithmetic number, because the mean of its divisors is an integer number (10506001620).

Almost surely, 2^21012003239 is an apocalyptic number.

21012003239 is a deficient number, since it is larger than the sum of its proper divisors (1).

21012003239 is an equidigital number, since it uses as much as digits as its factorization.

21012003239 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 648, while the sum is 23.

The spelling of 21012003239 in words is "twenty-one billion, twelve million, three thousand, two hundred thirty-nine".