138568709 has 2 divisors, whose sum is σ = 138568710. Its totient is φ = 138568708.

The previous prime is 138568697. The next prime is 138568723. The reversal of 138568709 is 907865831.

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., 98208100 + 40360609 = 9910^2 + 6353^2 .

It is a cyclic number.

It is not a de Polignac number, because 138568709 - 2⁸ = 138568453 is a prime.

It is a super-2 number, since 2×138568709² = 38402574227853362, which contains 22 as substring.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (138568769) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 69284354 + 69284355.

It is an arithmetic number, because the mean of its divisors is an integer number (69284355).

Almost surely, 2^138568709 is an apocalyptic number.

It is an amenable number.

138568709 is a deficient number, since it is larger than the sum of its proper divisors (1).

138568709 is an equidigital number, since it uses as much as digits as its factorization.

138568709 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 362880, while the sum is 47.

The square root of 138568709 is about 11771.5210996710. The cubic root of 138568709 is about 517.4738287931.

The spelling of 138568709 in words is "one hundred thirty-eight million, five hundred sixty-eight thousand, seven hundred nine".