138686797 has 2 divisors, whose sum is σ = 138686798. Its totient is φ = 138686796.

The previous prime is 138686783. The next prime is 138686809. The reversal of 138686797 is 797686831.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 129481641 + 9205156 = 11379^2 + 3034^2 .

It is an emirp because it is prime and its reverse (797686831) is a distict prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-138686797 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (138686747) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 69343398 + 69343399.

It is an arithmetic number, because the mean of its divisors is an integer number (69343399).

Almost surely, 2^138686797 is an apocalyptic number.

It is an amenable number.

138686797 is a deficient number, since it is larger than the sum of its proper divisors (1).

138686797 is an equidigital number, since it uses as much as digits as its factorization.

138686797 is an evil number, because the sum of its binary digits is even.

The product of its digits is 3048192, while the sum is 55.

The square root of 138686797 is about 11776.5358658648. The cubic root of 138686797 is about 517.6207838058.

The spelling of 138686797 in words is "one hundred thirty-eight million, six hundred eighty-six thousand, seven hundred ninety-seven".