68240509 has 4 divisors (see below), whose sum is σ = 70593660. Its totient is φ = 65887360.

The previous prime is 68240507. The next prime is 68240561. The reversal of 68240509 is 90504286.

It is a happy number.

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

It can be written as a sum of positive squares in 2 ways, for example, as 11539609 + 56700900 = 3397^2 + 7530^2 .

It is a cyclic number.

It is not a de Polignac number, because 68240509 - 2¹ = 68240507 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (68240503) 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 in 3 ways as a sum of consecutive naturals, for example, 1176532 + ... + 1176589.

It is an arithmetic number, because the mean of its divisors is an integer number (17648415).

Almost surely, 2^68240509 is an apocalyptic number.

It is an amenable number.

68240509 is a deficient number, since it is larger than the sum of its proper divisors (2353151).

68240509 is a wasteful number, since it uses less digits than its factorization.

68240509 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2353150.

The product of its (nonzero) digits is 17280, while the sum is 34.

The square root of 68240509 is about 8260.7813795064. The cubic root of 68240509 is about 408.6461571010.

The spelling of 68240509 in words is "sixty-eight million, two hundred forty thousand, five hundred nine".