138390 has 32 divisors (see below), whose sum is σ = 380160. Its totient is φ = 31584.

The previous prime is 138389. The next prime is 138401. The reversal of 138390 is 93831.

Added to its reverse (93831) it gives a triangular number (232221 = T₆₈₁).

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 138390.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 120 + ... + 539.

It is an arithmetic number, because the mean of its divisors is an integer number (11880).

2¹³⁸³⁹⁰ is an apocalyptic number.

138390 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

138390 is an abundant number, since it is smaller than the sum of its proper divisors (241770).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

138390 is a wasteful number, since it uses less digits than its factorization.

138390 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 676.

The product of its (nonzero) digits is 648, while the sum is 24.

The square root of 138390 is about 372.0080644287. The cubic root of 138390 is about 51.7251274906.

Adding to 138390 its reverse (93831), we get a triangular number (232221 = T₆₈₁).

It can be divided in two parts, 138 and 390, that added together give a triangular number (528 = T₃₂).

The spelling of 138390 in words is "one hundred thirty-eight thousand, three hundred ninety".