21220131239 has 2 divisors, whose sum is σ = 21220131240. Its totient is φ = 21220131238.

The previous prime is 21220131211. The next prime is 21220131241. The reversal of 21220131239 is 93213102212.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21220131239 is a prime.

It is a super-3 number, since 3×21220131239³ (a number of 32 digits) contains 333 as substring.

Together with 21220131241, 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 (21220131299) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10610065619 + 10610065620.

It is an arithmetic number, because the mean of its divisors is an integer number (10610065620).

Almost surely, 2^21220131239 is an apocalyptic number.

21220131239 is a deficient number, since it is larger than the sum of its proper divisors (1).

21220131239 is an equidigital number, since it uses as much as digits as its factorization.

21220131239 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 1296, while the sum is 26.

The spelling of 21220131239 in words is "twenty-one billion, two hundred twenty million, one hundred thirty-one thousand, two hundred thirty-nine".