1243131257 has 2 divisors, whose sum is σ = 1243131258. Its totient is φ = 1243131256.

The previous prime is 1243131203. The next prime is 1243131269. The reversal of 1243131257 is 7521313421.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 802928896 + 440202361 = 28336^2 + 20981^2 .

It is a cyclic number.

It is not a de Polignac number, because 1243131257 - 2²² = 1238936953 is a prime.

It is not a weakly prime, because it can be changed into another prime (1243101257) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 621565628 + 621565629.

It is an arithmetic number, because the mean of its divisors is an integer number (621565629).

Almost surely, 2^1243131257 is an apocalyptic number.

It is an amenable number.

1243131257 is a deficient number, since it is larger than the sum of its proper divisors (1).

1243131257 is an equidigital number, since it uses as much as digits as its factorization.

1243131257 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 5040, while the sum is 29.

The square root of 1243131257 is about 35258.0665522090. The cubic root of 1243131257 is about 1075.2406187898.

Adding to 1243131257 its reverse (7521313421), we get a palindrome (8764444678).

The spelling of 1243131257 in words is "one billion, two hundred forty-three million, one hundred thirty-one thousand, two hundred fifty-seven".