138553 has 4 divisors (see below), whose sum is σ = 139300. Its totient is φ = 137808.

The previous prime is 138547. The next prime is 138559. The reversal of 138553 is 355831.

It is a happy number.

138553 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length, and also an emirpimes, since its reverse is a distinct semiprime: 355831 = 7 ⋅50833.

It is an interprime number because it is at equal distance from previous prime (138547) and next prime (138559).

It can be written as a sum of positive squares in 2 ways, for example, as 97344 + 41209 = 312^2 + 203^2 .

It is a cyclic number.

It is not a de Polignac number, because 138553 - 2⁹ = 138041 is a prime.

It is a Duffinian number.

138553 is a lucky number.

It is not an unprimeable number, because it can be changed into a prime (138559) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 151 + ... + 547.

It is an arithmetic number, because the mean of its divisors is an integer number (34825).

2¹³⁸⁵⁵³ is an apocalyptic number.

It is an amenable number.

138553 is a deficient number, since it is larger than the sum of its proper divisors (747).

138553 is an equidigital number, since it uses as much as digits as its factorization.

138553 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 746.

The product of its digits is 1800, while the sum is 25.

The square root of 138553 is about 372.2270812286. The cubic root of 138553 is about 51.7454273384.

The spelling of 138553 in words is "one hundred thirty-eight thousand, five hundred fifty-three".