1240635243 has 4 divisors (see below), whose sum is σ = 1654180328. Its totient is φ = 827090160.

The previous prime is 1240635223. The next prime is 1240635251. The reversal of 1240635243 is 3425360421.

It is a semiprime because it is the product of two primes.

It is not a de Polignac number, because 1240635243 - 2⁸ = 1240634987 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 1240635243.

It is not an unprimeable number, because it can be changed into a prime (1240635223) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 206772538 + ... + 206772543.

It is an arithmetic number, because the mean of its divisors is an integer number (413545082).

Almost surely, 2^1240635243 is an apocalyptic number.

1240635243 is a deficient number, since it is larger than the sum of its proper divisors (413545085).

1240635243 is an equidigital number, since it uses as much as digits as its factorization.

1240635243 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 413545084.

The product of its (nonzero) digits is 17280, while the sum is 30.

The square root of 1240635243 is about 35222.6524129004. The cubic root of 1240635243 is about 1074.5204980310.

Adding to 1240635243 its reverse (3425360421), we get a palindrome (4665995664).

The spelling of 1240635243 in words is "one billion, two hundred forty million, six hundred thirty-five thousand, two hundred forty-three".