138478913 has 2 divisors, whose sum is σ = 138478914. Its totient is φ = 138478912.

The previous prime is 138478817. The next prime is 138478919. The reversal of 138478913 is 319874831.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 127870864 + 10608049 = 11308^2 + 3257^2 .

It is a cyclic number.

It is not a de Polignac number, because 138478913 - 2¹⁶ = 138413377 is a prime.

It is not a weakly prime, because it can be changed into another prime (138478919) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 69239456 + 69239457.

It is an arithmetic number, because the mean of its divisors is an integer number (69239457).

Almost surely, 2^138478913 is an apocalyptic number.

It is an amenable number.

138478913 is a deficient number, since it is larger than the sum of its proper divisors (1).

138478913 is an equidigital number, since it uses as much as digits as its factorization.

138478913 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 145152, while the sum is 44.

The square root of 138478913 is about 11767.7063610544. The cubic root of 138478913 is about 517.3620259646.

The spelling of 138478913 in words is "one hundred thirty-eight million, four hundred seventy-eight thousand, nine hundred thirteen".