257221207 has 2 divisors, whose sum is σ = 257221208. Its totient is φ = 257221206.

The previous prime is 257221189. The next prime is 257221253. The reversal of 257221207 is 702122752.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 257221207 - 2¹¹ = 257219159 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (257221007) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 128610603 + 128610604.

It is an arithmetic number, because the mean of its divisors is an integer number (128610604).

Almost surely, 2^257221207 is an apocalyptic number.

257221207 is a deficient number, since it is larger than the sum of its proper divisors (1).

257221207 is an equidigital number, since it uses as much as digits as its factorization.

257221207 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 3920, while the sum is 28.

The square root of 257221207 is about 16038.1173146975. The cubic root of 257221207 is about 635.9684785546.

Adding to 257221207 its reverse (702122752), we get a palindrome (959343959).

The spelling of 257221207 in words is "two hundred fifty-seven million, two hundred twenty-one thousand, two hundred seven".