385257221 has 2 divisors, whose sum is σ = 385257222. Its totient is φ = 385257220.

The previous prime is 385257211. The next prime is 385257269. The reversal of 385257221 is 122752583.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 346332100 + 38925121 = 18610^2 + 6239^2 .

It is an emirp because it is prime and its reverse (122752583) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 385257221 - 2¹⁴ = 385240837 is a 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 (385257211) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 192628610 + 192628611.

It is an arithmetic number, because the mean of its divisors is an integer number (192628611).

Almost surely, 2^385257221 is an apocalyptic number.

It is an amenable number.

385257221 is a deficient number, since it is larger than the sum of its proper divisors (1).

385257221 is an equidigital number, since it uses as much as digits as its factorization.

385257221 is an evil number, because the sum of its binary digits is even.

The product of its digits is 33600, while the sum is 35.

The square root of 385257221 is about 19627.9703739332. The cubic root of 385257221 is about 727.6406098789.

The spelling of 385257221 in words is "three hundred eighty-five million, two hundred fifty-seven thousand, two hundred twenty-one".