138780913 has 2 divisors, whose sum is σ = 138780914. Its totient is φ = 138780912.

The previous prime is 138780869. The next prime is 138780937. The reversal of 138780913 is 319087831.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 95589729 + 43191184 = 9777^2 + 6572^2 .

It is an emirp because it is prime and its reverse (319087831) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 138780913 - 2²¹ = 136683761 is a prime.

It is a super-2 number, since 2×138780913² = 38520283626227138, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (138780953) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 69390456 + 69390457.

It is an arithmetic number, because the mean of its divisors is an integer number (69390457).

Almost surely, 2^138780913 is an apocalyptic number.

It is an amenable number.

138780913 is a deficient number, since it is larger than the sum of its proper divisors (1).

138780913 is an equidigital number, since it uses as much as digits as its factorization.

138780913 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 36288, while the sum is 40.

The square root of 138780913 is about 11780.5311000820. The cubic root of 138780913 is about 517.7378470564.

The spelling of 138780913 in words is "one hundred thirty-eight million, seven hundred eighty thousand, nine hundred thirteen".