21210343439 has 2 divisors, whose sum is σ = 21210343440. Its totient is φ = 21210343438.

The previous prime is 21210343417. The next prime is 21210343477. The reversal of 21210343439 is 93434301212.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 21210343439 - 2³² = 16915376143 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21210343339) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10605171719 + 10605171720.

It is an arithmetic number, because the mean of its divisors is an integer number (10605171720).

Almost surely, 2^21210343439 is an apocalyptic number.

21210343439 is a deficient number, since it is larger than the sum of its proper divisors (1).

21210343439 is an equidigital number, since it uses as much as digits as its factorization.

21210343439 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 32.

The spelling of 21210343439 in words is "twenty-one billion, two hundred ten million, three hundred forty-three thousand, four hundred thirty-nine".