68537509 has 2 divisors, whose sum is σ = 68537510. Its totient is φ = 68537508.

The previous prime is 68537479. The next prime is 68537543. The reversal of 68537509 is 90573586.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 67732900 + 804609 = 8230^2 + 897^2 .

It is a cyclic number.

It is not a de Polignac number, because 68537509 - 2⁹ = 68536997 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (68537549) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 34268754 + 34268755.

It is an arithmetic number, because the mean of its divisors is an integer number (34268755).

Almost surely, 2^68537509 is an apocalyptic number.

It is an amenable number.

68537509 is a deficient number, since it is larger than the sum of its proper divisors (1).

68537509 is an equidigital number, since it uses as much as digits as its factorization.

68537509 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 226800, while the sum is 43.

The square root of 68537509 is about 8278.7383700658. The cubic root of 68537509 is about 409.2381430064.

The spelling of 68537509 in words is "sixty-eight million, five hundred thirty-seven thousand, five hundred nine".