1240565761 has 2 divisors, whose sum is σ = 1240565762. Its totient is φ = 1240565760.

The previous prime is 1240565759. The next prime is 1240565771. The reversal of 1240565761 is 1675650421.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 993447361 + 247118400 = 31519^2 + 15720^2 .

It is a cyclic number.

It is not a de Polignac number, because 1240565761 - 2¹ = 1240565759 is a prime.

Together with 1240565759, it forms a pair of twin primes.

It is a self number, because there is not a number n which added to its sum of digits gives 1240565761.

It is not a weakly prime, because it can be changed into another prime (1240565771) 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, 620282880 + 620282881.

It is an arithmetic number, because the mean of its divisors is an integer number (620282881).

Almost surely, 2^1240565761 is an apocalyptic number.

It is an amenable number.

1240565761 is a deficient number, since it is larger than the sum of its proper divisors (1).

1240565761 is an equidigital number, since it uses as much as digits as its factorization.

1240565761 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 50400, while the sum is 37.

The square root of 1240565761 is about 35221.6660735974. Note that the first 3 decimals coincide. The cubic root of 1240565761 is about 1074.5004380853.

The spelling of 1240565761 in words is "one billion, two hundred forty million, five hundred sixty-five thousand, seven hundred sixty-one".