21213231239 has 2 divisors, whose sum is σ = 21213231240. Its totient is φ = 21213231238.

The previous prime is 21213231233. The next prime is 21213231241. The reversal of 21213231239 is 93213231212.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 21213231239 - 2¹² = 21213227143 is a prime.

Together with 21213231241, 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 (21213231233) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10606615619 + 10606615620.

It is an arithmetic number, because the mean of its divisors is an integer number (10606615620).

Almost surely, 2^21213231239 is an apocalyptic number.

21213231239 is a deficient number, since it is larger than the sum of its proper divisors (1).

21213231239 is an equidigital number, since it uses as much as digits as its factorization.

21213231239 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 3888, while the sum is 29.

The spelling of 21213231239 in words is "twenty-one billion, two hundred thirteen million, two hundred thirty-one thousand, two hundred thirty-nine".