257721043 has 2 divisors, whose sum is σ = 257721044. Its totient is φ = 257721042.

The previous prime is 257721031. The next prime is 257721047. The reversal of 257721043 is 340127752.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 257721043 - 2⁹ = 257720531 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 257720996 and 257721014.

It is not a weakly prime, because it can be changed into another prime (257721047) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 128860521 + 128860522.

It is an arithmetic number, because the mean of its divisors is an integer number (128860522).

Almost surely, 2^257721043 is an apocalyptic number.

257721043 is a deficient number, since it is larger than the sum of its proper divisors (1).

257721043 is an equidigital number, since it uses as much as digits as its factorization.

257721043 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 11760, while the sum is 31.

The square root of 257721043 is about 16053.6925035956. The cubic root of 257721043 is about 636.3801530858.

Adding to 257721043 its reverse (340127752), we get a palindrome (597848795).

The spelling of 257721043 in words is "two hundred fifty-seven million, seven hundred twenty-one thousand, forty-three".