257143409 has 2 divisors, whose sum is σ = 257143410. Its totient is φ = 257143408.

The previous prime is 257143399. The next prime is 257143423. The reversal of 257143409 is 904341752.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 245392225 + 11751184 = 15665^2 + 3428^2 .

It is a cyclic number.

It is not a de Polignac number, because 257143409 - 2²⁴ = 240366193 is a prime.

It is a super-2 number, since 2×257143409² = 132245465584282562, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (257143429) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 128571704 + 128571705.

It is an arithmetic number, because the mean of its divisors is an integer number (128571705).

Almost surely, 2^257143409 is an apocalyptic number.

It is an amenable number.

257143409 is a deficient number, since it is larger than the sum of its proper divisors (1).

257143409 is an equidigital number, since it uses as much as digits as its factorization.

257143409 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 30240, while the sum is 35.

The square root of 257143409 is about 16035.6917219059. The cubic root of 257143409 is about 635.9043546755.

The spelling of 257143409 in words is "two hundred fifty-seven million, one hundred forty-three thousand, four hundred nine".