139740509 has 2 divisors, whose sum is σ = 139740510. Its totient is φ = 139740508.

The previous prime is 139740499. The next prime is 139740521. The reversal of 139740509 is 905047931.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 93799225 + 45941284 = 9685^2 + 6778^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-139740509 is a prime.

It is a Sophie Germain prime.

It is a Chen prime.

It is a Curzon number.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (139740539) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 69870254 + 69870255.

It is an arithmetic number, because the mean of its divisors is an integer number (69870255).

Almost surely, 2^139740509 is an apocalyptic number.

It is an amenable number.

139740509 is a deficient number, since it is larger than the sum of its proper divisors (1).

139740509 is an equidigital number, since it uses as much as digits as its factorization.

139740509 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 34020, while the sum is 38.

The square root of 139740509 is about 11821.1889841927. The cubic root of 139740509 is about 518.9284009421.

The spelling of 139740509 in words is "one hundred thirty-nine million, seven hundred forty thousand, five hundred nine".