257721253 has 2 divisors, whose sum is σ = 257721254. Its totient is φ = 257721252.

The previous prime is 257721239. The next prime is 257721283. The reversal of 257721253 is 352127752.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 201441249 + 56280004 = 14193^2 + 7502^2 .

It is a cyclic number.

It is not a de Polignac number, because 257721253 - 2⁵ = 257721221 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (257721283) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 128860626 + 128860627.

It is an arithmetic number, because the mean of its divisors is an integer number (128860627).

Almost surely, 2^257721253 is an apocalyptic number.

It is an amenable number.

257721253 is a deficient number, since it is larger than the sum of its proper divisors (1).

257721253 is an equidigital number, since it uses as much as digits as its factorization.

257721253 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 29400, while the sum is 34.

The square root of 257721253 is about 16053.6990441456. The cubic root of 257721253 is about 636.3803259340.

The spelling of 257721253 in words is "two hundred fifty-seven million, seven hundred twenty-one thousand, two hundred fifty-three".