138578438 has 16 divisors (see below), whose sum is σ = 220266240. Its totient is φ = 65205000.

The previous prime is 138578423. The next prime is 138578449. The reversal of 138578438 is 834875831.

It is a happy number.

It is a junction number, because it is equal to n+sod(n) for n = 138578392 and 138578401.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 6338 + ... + 17813.

It is an arithmetic number, because the mean of its divisors is an integer number (13766640).

Almost surely, 2^138578438 is an apocalyptic number.

138578438 is a deficient number, since it is larger than the sum of its proper divisors (81687802).

138578438 is a wasteful number, since it uses less digits than its factorization.

138578438 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 24323.

The product of its digits is 645120, while the sum is 47.

The square root of 138578438 is about 11771.9343355287. The cubic root of 138578438 is about 517.4859392354.

The spelling of 138578438 in words is "one hundred thirty-eight million, five hundred seventy-eight thousand, four hundred thirty-eight".