221231239 has 2 divisors, whose sum is σ = 221231240. Its totient is φ = 221231238.

The previous prime is 221231233. The next prime is 221231279. The reversal of 221231239 is 932132122.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 221231239 - 2⁵ = 221231207 is a prime.

It is a super-3 number, since 3×221231239³ (a number of 26 digits) contains 333 as substring. Note that it is a super-d number also for d = 2.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (221231233) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 110615619 + 110615620.

It is an arithmetic number, because the mean of its divisors is an integer number (110615620).

Almost surely, 2^221231239 is an apocalyptic number.

221231239 is a deficient number, since it is larger than the sum of its proper divisors (1).

221231239 is an equidigital number, since it uses as much as digits as its factorization.

221231239 is an evil number, because the sum of its binary digits is even.

The product of its digits is 1296, while the sum is 25.

The square root of 221231239 is about 14873.8441231579. The cubic root of 221231239 is about 604.8051545672.

The spelling of 221231239 in words is "two hundred twenty-one million, two hundred thirty-one thousand, two hundred thirty-nine".