138756913 has 2 divisors, whose sum is σ = 138756914. Its totient is φ = 138756912.

The previous prime is 138756901. The next prime is 138756979. The reversal of 138756913 is 319657831.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 136142224 + 2614689 = 11668^2 + 1617^2 .

It is a cyclic number.

It is not a de Polignac number, because 138756913 - 2¹⁷ = 138625841 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 138756913.

It is not a weakly prime, because it can be changed into another prime (138756413) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 69378456 + 69378457.

It is an arithmetic number, because the mean of its divisors is an integer number (69378457).

Almost surely, 2^138756913 is an apocalyptic number.

It is an amenable number.

138756913 is a deficient number, since it is larger than the sum of its proper divisors (1).

138756913 is an equidigital number, since it uses as much as digits as its factorization.

138756913 is an evil number, because the sum of its binary digits is even.

The product of its digits is 136080, while the sum is 43.

The square root of 138756913 is about 11779.5124262424. The cubic root of 138756913 is about 517.7080004336.

The spelling of 138756913 in words is "one hundred thirty-eight million, seven hundred fifty-six thousand, nine hundred thirteen".