221242139 has 2 divisors, whose sum is σ = 221242140. Its totient is φ = 221242138.

The previous prime is 221242127. The next prime is 221242157. The reversal of 221242139 is 931242122.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 221242139 - 2²⁰ = 220193563 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (221242169) 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, 110621069 + 110621070.

It is an arithmetic number, because the mean of its divisors is an integer number (110621070).

Almost surely, 2^221242139 is an apocalyptic number.

221242139 is a deficient number, since it is larger than the sum of its proper divisors (1).

221242139 is an equidigital number, since it uses as much as digits as its factorization.

221242139 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 1728, while the sum is 26.

The square root of 221242139 is about 14874.2105336720. The cubic root of 221242139 is about 604.8150872632.

The spelling of 221242139 in words is "two hundred twenty-one million, two hundred forty-two thousand, one hundred thirty-nine".