257672321 has 2 divisors, whose sum is σ = 257672322. Its totient is φ = 257672320.

The previous prime is 257672309. The next prime is 257672323. The reversal of 257672321 is 123276752.

257672321 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 253924225 + 3748096 = 15935^2 + 1936^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-257672321 is a prime.

Together with 257672323, it forms a pair of twin primes.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (257672323) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 128836160 + 128836161.

It is an arithmetic number, because the mean of its divisors is an integer number (128836161).

Almost surely, 2^257672321 is an apocalyptic number.

It is an amenable number.

257672321 is a deficient number, since it is larger than the sum of its proper divisors (1).

257672321 is an equidigital number, since it uses as much as digits as its factorization.

257672321 is an evil number, because the sum of its binary digits is even.

The product of its digits is 35280, while the sum is 35.

The square root of 257672321 is about 16052.1749616680. The cubic root of 257672321 is about 636.3400481368.

The spelling of 257672321 in words is "two hundred fifty-seven million, six hundred seventy-two thousand, three hundred twenty-one".