385706221 has 2 divisors, whose sum is σ = 385706222. Its totient is φ = 385706220.

The previous prime is 385706219. The next prime is 385706249. The reversal of 385706221 is 122607583.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 224670121 + 161036100 = 14989^2 + 12690^2 .

It is a cyclic number.

It is not a de Polignac number, because 385706221 - 2¹ = 385706219 is a prime.

Together with 385706219, it forms a pair of twin primes.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (385706291) 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, 192853110 + 192853111.

It is an arithmetic number, because the mean of its divisors is an integer number (192853111).

Almost surely, 2^385706221 is an apocalyptic number.

It is an amenable number.

385706221 is a deficient number, since it is larger than the sum of its proper divisors (1).

385706221 is an equidigital number, since it uses as much as digits as its factorization.

385706221 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 20160, while the sum is 34.

The square root of 385706221 is about 19639.4048025901. The cubic root of 385706221 is about 727.9231776250.

The spelling of 385706221 in words is "three hundred eighty-five million, seven hundred six thousand, two hundred twenty-one".