221973239 has 2 divisors, whose sum is σ = 221973240. Its totient is φ = 221973238.

The previous prime is 221973187. The next prime is 221973247. The reversal of 221973239 is 932379122.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 221973239 - 2⁸ = 221972983 is a prime.

It is a super-2 number, since 2×221973239² = 98544237664302242, which contains 22 as substring.

It is a Sophie Germain prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (221973289) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 110986619 + 110986620.

It is an arithmetic number, because the mean of its divisors is an integer number (110986620).

Almost surely, 2^221973239 is an apocalyptic number.

221973239 is a deficient number, since it is larger than the sum of its proper divisors (1).

221973239 is an equidigital number, since it uses as much as digits as its factorization.

221973239 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 40824, while the sum is 38.

The square root of 221973239 is about 14898.7663583265. The cubic root of 221973239 is about 605.4805634685.

The spelling of 221973239 in words is "two hundred twenty-one million, nine hundred seventy-three thousand, two hundred thirty-nine".