138749 has 6 divisors (see below), whose sum is σ = 150426. Its totient is φ = 127920.

The previous prime is 138739. The next prime is 138763. The reversal of 138749 is 947831.

It can be written as a sum of positive squares in 3 ways, for example, as 1849 + 136900 = 43^2 + 370^2 .

It is not a de Polignac number, because 138749 - 2⁸ = 138493 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (138739) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 242 + ... + 579.

It is an arithmetic number, because the mean of its divisors is an integer number (25071).

2¹³⁸⁷⁴⁹ is an apocalyptic number.

It is an amenable number.

138749 is a deficient number, since it is larger than the sum of its proper divisors (11677).

138749 is an equidigital number, since it uses as much as digits as its factorization.

138749 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 847 (or 834 counting only the distinct ones).

The product of its digits is 6048, while the sum is 32.

The square root of 138749 is about 372.4902683293. The cubic root of 138749 is about 51.7698158999.

The spelling of 138749 in words is "one hundred thirty-eight thousand, seven hundred forty-nine".