1240312757 has 2 divisors, whose sum is σ = 1240312758. Its totient is φ = 1240312756.

The previous prime is 1240312721. The next prime is 1240312783. The reversal of 1240312757 is 7572130421.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1029511396 + 210801361 = 32086^2 + 14519^2 .

It is a cyclic number.

It is not a de Polignac number, because 1240312757 - 2¹⁶ = 1240247221 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1240311757) 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, 620156378 + 620156379.

It is an arithmetic number, because the mean of its divisors is an integer number (620156379).

Almost surely, 2^1240312757 is an apocalyptic number.

It is an amenable number.

1240312757 is a deficient number, since it is larger than the sum of its proper divisors (1).

1240312757 is an equidigital number, since it uses as much as digits as its factorization.

1240312757 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 11760, while the sum is 32.

The square root of 1240312757 is about 35218.0742943165. The cubic root of 1240312757 is about 1074.4273877077.

The spelling of 1240312757 in words is "one billion, two hundred forty million, three hundred twelve thousand, seven hundred fifty-seven".