201221939 has 2 divisors, whose sum is σ = 201221940. Its totient is φ = 201221938.

The previous prime is 201221929. The next prime is 201221959. The reversal of 201221939 is 939122102.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 201221939 - 2¹² = 201217843 is a prime.

It is a Sophie Germain prime.

It is not a weakly prime, because it can be changed into another prime (201221929) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 100610969 + 100610970.

It is an arithmetic number, because the mean of its divisors is an integer number (100610970).

Almost surely, 2^201221939 is an apocalyptic number.

201221939 is a deficient number, since it is larger than the sum of its proper divisors (1).

201221939 is an equidigital number, since it uses as much as digits as its factorization.

201221939 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 1944, while the sum is 29.

The square root of 201221939 is about 14185.2719043380. The cubic root of 201221939 is about 585.9921207497.

The spelling of 201221939 in words is "two hundred one million, two hundred twenty-one thousand, nine hundred thirty-nine".