138815519 has 2 divisors, whose sum is σ = 138815520. Its totient is φ = 138815518.

The previous prime is 138815513. The next prime is 138815531. The reversal of 138815519 is 915518831.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 138815519 - 2¹² = 138811423 is a prime.

It is a super-2 number, since 2×138815519² = 38539496630478722, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (138815513) 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, 69407759 + 69407760.

It is an arithmetic number, because the mean of its divisors is an integer number (69407760).

Almost surely, 2^138815519 is an apocalyptic number.

138815519 is a deficient number, since it is larger than the sum of its proper divisors (1).

138815519 is an equidigital number, since it uses as much as digits as its factorization.

138815519 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 43200, while the sum is 41.

The square root of 138815519 is about 11781.9997878119. Note that the first 3 decimals coincide. The cubic root of 138815519 is about 517.7808773418.

The spelling of 138815519 in words is "one hundred thirty-eight million, eight hundred fifteen thousand, five hundred nineteen".