257051681 has 2 divisors, whose sum is σ = 257051682. Its totient is φ = 257051680.

The previous prime is 257051651. The next prime is 257051689. The reversal of 257051681 is 186150752.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 185395456 + 71656225 = 13616^2 + 8465^2 .

It is a cyclic number.

It is not a de Polignac number, because 257051681 - 2¹⁴ = 257035297 is a prime.

It is a super-2 number, since 2×257051681² = 132151133409851522, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (257051689) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 128525840 + 128525841.

It is an arithmetic number, because the mean of its divisors is an integer number (128525841).

Almost surely, 2^257051681 is an apocalyptic number.

It is an amenable number.

257051681 is a deficient number, since it is larger than the sum of its proper divisors (1).

257051681 is an equidigital number, since it uses as much as digits as its factorization.

257051681 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 16800, while the sum is 35.

The square root of 257051681 is about 16032.8313469580. The cubic root of 257051681 is about 635.8287325780.

The spelling of 257051681 in words is "two hundred fifty-seven million, fifty-one thousand, six hundred eighty-one".