257321216 has 18 divisors (see below), whose sum is σ = 513637782. Its totient is φ = 128660480.

The previous prime is 257321191. The next prime is 257321257. The reversal of 257321216 is 612123752.

It is a happy number.

It can be written as a sum of positive squares in only one way, i.e., 193321216 + 64000000 = 13904^2 + 8000^2 .

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 502325 + ... + 502836.

Almost surely, 2^257321216 is an apocalyptic number.

It is an amenable number.

257321216 is a deficient number, since it is larger than the sum of its proper divisors (256316566).

257321216 is an equidigital number, since it uses as much as digits as its factorization.

257321216 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1005177 (or 1005163 counting only the distinct ones).

The product of its digits is 5040, while the sum is 29.

The square root of 257321216 is about 16041.2348651842. The cubic root of 257321216 is about 636.0508905390.

Adding to 257321216 its reverse (612123752), we get a palindrome (869444968).

The spelling of 257321216 in words is "two hundred fifty-seven million, three hundred twenty-one thousand, two hundred sixteen".