138928133 has 4 divisors (see below), whose sum is σ = 146240160. Its totient is φ = 131616108.

The previous prime is 138928123. The next prime is 138928177. The reversal of 138928133 is 331829831.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 331829831 = 11321 ⋅29311.

It is a cyclic number.

It is not a de Polignac number, because 138928133 - 2²⁰ = 137879557 is a prime.

It is a super-2 number, since 2×138928133² = 38602052277731378, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (138928123) 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, 3655985 + ... + 3656022.

It is an arithmetic number, because the mean of its divisors is an integer number (36560040).

Almost surely, 2^138928133 is an apocalyptic number.

It is an amenable number.

138928133 is a deficient number, since it is larger than the sum of its proper divisors (7312027).

138928133 is an equidigital number, since it uses as much as digits as its factorization.

138928133 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7312026.

The product of its digits is 31104, while the sum is 38.

The square root of 138928133 is about 11786.7778888040. Note that the first 3 decimals coincide. The cubic root of 138928133 is about 517.9208559634.

The spelling of 138928133 in words is "one hundred thirty-eight million, nine hundred twenty-eight thousand, one hundred thirty-three".