138329399 has 4 divisors (see below), whose sum is σ = 148970136. Its totient is φ = 127688664.

The previous prime is 138329381. The next prime is 138329423. The reversal of 138329399 is 993923831.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 993923831 = 10729 ⋅92639.

It is a cyclic number.

It is not a de Polignac number, because 138329399 - 2¹² = 138325303 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (138329299) 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 in 3 ways as a sum of consecutive naturals, for example, 5320349 + ... + 5320374.

It is an arithmetic number, because the mean of its divisors is an integer number (37242534).

Almost surely, 2^138329399 is an apocalyptic number.

138329399 is a deficient number, since it is larger than the sum of its proper divisors (10640737).

138329399 is a wasteful number, since it uses less digits than its factorization.

138329399 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10640736.

The product of its digits is 314928, while the sum is 47.

The square root of 138329399 is about 11761.3519205914. The cubic root of 138329399 is about 517.1757624150.

It can be divided in two parts, 138329 and 399, that multiplied together give a triangular number (55193271 = T₁₀₅₀₆).

The spelling of 138329399 in words is "one hundred thirty-eight million, three hundred twenty-nine thousand, three hundred ninety-nine".