1240443257 has 2 divisors, whose sum is σ = 1240443258. Its totient is φ = 1240443256.

The previous prime is 1240443247. The next prime is 1240443263. The reversal of 1240443257 is 7523440421.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 760877056 + 479566201 = 27584^2 + 21899^2 .

It is a cyclic number.

It is not a de Polignac number, because 1240443257 - 2¹⁸ = 1240181113 is a prime.

It is not a weakly prime, because it can be changed into another prime (1240443247) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 620221628 + 620221629.

It is an arithmetic number, because the mean of its divisors is an integer number (620221629).

Almost surely, 2^1240443257 is an apocalyptic number.

It is an amenable number.

1240443257 is a deficient number, since it is larger than the sum of its proper divisors (1).

1240443257 is an equidigital number, since it uses as much as digits as its factorization.

1240443257 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 26880, while the sum is 32.

The square root of 1240443257 is about 35219.9269874314. The cubic root of 1240443257 is about 1074.4650684878.

Adding to 1240443257 its reverse (7523440421), we get a palindrome (8763883678).

The spelling of 1240443257 in words is "one billion, two hundred forty million, four hundred forty-three thousand, two hundred fifty-seven".