138945 has 16 divisors (see below), whose sum is σ = 227520. Its totient is φ = 72384.

The previous prime is 138937. The next prime is 138959. The reversal of 138945 is 549831.

It is not a de Polignac number, because 138945 - 2³ = 138937 is a prime.

It is an Ulam number.

It is a Curzon number.

138945 is a lucky 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, 807 + ... + 963.

It is an arithmetic number, because the mean of its divisors is an integer number (14220).

2¹³⁸⁹⁴⁵ is an apocalyptic number.

138945 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

It is an amenable number.

138945 is a deficient number, since it is larger than the sum of its proper divisors (88575).

138945 is a wasteful number, since it uses less digits than its factorization.

138945 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 224.

The product of its digits is 4320, while the sum is 30.

The square root of 138945 is about 372.7532696034. The cubic root of 138945 is about 51.7941815043.

The spelling of 138945 in words is "one hundred thirty-eight thousand, nine hundred forty-five".