138278479 has 2 divisors, whose sum is σ = 138278480. Its totient is φ = 138278478.

The previous prime is 138278471. The next prime is 138278501. The reversal of 138278479 is 974872831.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 138278479 - 2³ = 138278471 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (138278471) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 69139239 + 69139240.

It is an arithmetic number, because the mean of its divisors is an integer number (69139240).

Almost surely, 2^138278479 is an apocalyptic number.

138278479 is a deficient number, since it is larger than the sum of its proper divisors (1).

138278479 is an equidigital number, since it uses as much as digits as its factorization.

138278479 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 677376, while the sum is 49.

The square root of 138278479 is about 11759.1870042108. The cubic root of 138278479 is about 517.1122959791.

The spelling of 138278479 in words is "one hundred thirty-eight million, two hundred seventy-eight thousand, four hundred seventy-nine".