42440257 has 2 divisors, whose sum is σ = 42440258. Its totient is φ = 42440256.

The previous prime is 42440249. The next prime is 42440263. The reversal of 42440257 is 75204424.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 38241856 + 4198401 = 6184^2 + 2049^2 .

It is a cyclic number.

It is not a de Polignac number, because 42440257 - 2³ = 42440249 is a prime.

It is not a weakly prime, because it can be changed into another prime (42440287) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 21220128 + 21220129.

It is an arithmetic number, because the mean of its divisors is an integer number (21220129).

Almost surely, 2^42440257 is an apocalyptic number.

It is an amenable number.

42440257 is a deficient number, since it is larger than the sum of its proper divisors (1).

42440257 is an equidigital number, since it uses as much as digits as its factorization.

42440257 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 8960, while the sum is 28.

The square root of 42440257 is about 6514.6187148597. The cubic root of 42440257 is about 348.8130048081.

The spelling of 42440257 in words is "forty-two million, four hundred forty thousand, two hundred fifty-seven".