21210234239 has 2 divisors, whose sum is σ = 21210234240. Its totient is φ = 21210234238.

The previous prime is 21210234217. The next prime is 21210234289. The reversal of 21210234239 is 93243201212.

It is a happy number.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 21210234239 - 2²⁰ = 21209185663 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21210234289) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10605117119 + 10605117120.

It is an arithmetic number, because the mean of its divisors is an integer number (10605117120).

Almost surely, 2^21210234239 is an apocalyptic number.

21210234239 is a deficient number, since it is larger than the sum of its proper divisors (1).

21210234239 is an equidigital number, since it uses as much as digits as its factorization.

21210234239 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 5184, while the sum is 29.

The spelling of 21210234239 in words is "twenty-one billion, two hundred ten million, two hundred thirty-four thousand, two hundred thirty-nine".