257720461 has 2 divisors, whose sum is σ = 257720462. Its totient is φ = 257720460.

The previous prime is 257720423. The next prime is 257720483. The reversal of 257720461 is 164027752.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 195468361 + 62252100 = 13981^2 + 7890^2 .

It is a cyclic number.

It is not a de Polignac number, because 257720461 - 2²¹ = 255623309 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (257720401) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 128860230 + 128860231.

It is an arithmetic number, because the mean of its divisors is an integer number (128860231).

Almost surely, 2^257720461 is an apocalyptic number.

It is an amenable number.

257720461 is a deficient number, since it is larger than the sum of its proper divisors (1).

257720461 is an equidigital number, since it uses as much as digits as its factorization.

257720461 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 23520, while the sum is 34.

The square root of 257720461 is about 16053.6743769145. The cubic root of 257720461 is about 636.3796740491.

The spelling of 257720461 in words is "two hundred fifty-seven million, seven hundred twenty thousand, four hundred sixty-one".