21144209039 has 2 divisors, whose sum is σ = 21144209040. Its totient is φ = 21144209038.

The previous prime is 21144208979. The next prime is 21144209057. The reversal of 21144209039 is 93090244112.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 21144209039 - 2¹² = 21144204943 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21144209069) 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, 10572104519 + 10572104520.

It is an arithmetic number, because the mean of its divisors is an integer number (10572104520).

Almost surely, 2^21144209039 is an apocalyptic number.

21144209039 is a deficient number, since it is larger than the sum of its proper divisors (1).

21144209039 is an equidigital number, since it uses as much as digits as its factorization.

21144209039 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 15552, while the sum is 35.

The spelling of 21144209039 in words is "twenty-one billion, one hundred forty-four million, two hundred nine thousand, thirty-nine".