1243563749 has 2 divisors, whose sum is σ = 1243563750. Its totient is φ = 1243563748.

The previous prime is 1243563733. The next prime is 1243563767. The reversal of 1243563749 is 9473653421.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1170118849 + 73444900 = 34207^2 + 8570^2 .

It is a cyclic number.

It is not a de Polignac number, because 1243563749 - 2⁴ = 1243563733 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1243563449) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 621781874 + 621781875.

It is an arithmetic number, because the mean of its divisors is an integer number (621781875).

Almost surely, 2^1243563749 is an apocalyptic number.

It is an amenable number.

1243563749 is a deficient number, since it is larger than the sum of its proper divisors (1).

1243563749 is an equidigital number, since it uses as much as digits as its factorization.

1243563749 is an evil number, because the sum of its binary digits is even.

The product of its digits is 544320, while the sum is 44.

The square root of 1243563749 is about 35264.1992536340. The cubic root of 1243563749 is about 1075.3652983156.

The spelling of 1243563749 in words is "one billion, two hundred forty-three million, five hundred sixty-three thousand, seven hundred forty-nine".