1240879509 has 24 divisors (see below), whose sum is σ = 1913820480. Its totient is φ = 772877952.

The previous prime is 1240879483. The next prime is 1240879511. The reversal of 1240879509 is 9059780421.

It is not a de Polignac number, because 1240879509 - 2⁹ = 1240878997 is a prime.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1240879009) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 60804 + ... + 78605.

It is an arithmetic number, because the mean of its divisors is an integer number (79742520).

Almost surely, 2^1240879509 is an apocalyptic number.

It is an amenable number.

1240879509 is a deficient number, since it is larger than the sum of its proper divisors (672940971).

1240879509 is a wasteful number, since it uses less digits than its factorization.

1240879509 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 139481 (or 139478 counting only the distinct ones).

The product of its (nonzero) digits is 181440, while the sum is 45.

The square root of 1240879509 is about 35226.1196983148. The cubic root of 1240879509 is about 1074.5910134120.

The spelling of 1240879509 in words is "one billion, two hundred forty million, eight hundred seventy-nine thousand, five hundred nine".