1240346209 has 2 divisors, whose sum is σ = 1240346210. Its totient is φ = 1240346208.

The previous prime is 1240346171. The next prime is 1240346221. The reversal of 1240346209 is 9026430421.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1180128609 + 60217600 = 34353^2 + 7760^2 .

It is an emirp because it is prime and its reverse (9026430421) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 1240346209 - 2²⁷ = 1106128481 is a prime.

It is not a weakly prime, because it can be changed into another prime (1240346249) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 620173104 + 620173105.

It is an arithmetic number, because the mean of its divisors is an integer number (620173105).

Almost surely, 2^1240346209 is an apocalyptic number.

It is an amenable number.

1240346209 is a deficient number, since it is larger than the sum of its proper divisors (1).

1240346209 is an equidigital number, since it uses as much as digits as its factorization.

1240346209 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 10368, while the sum is 31.

The square root of 1240346209 is about 35218.5492177063. The cubic root of 1240346209 is about 1074.4370469440.

The spelling of 1240346209 in words is "one billion, two hundred forty million, three hundred forty-six thousand, two hundred nine".