138969489 has 4 divisors (see below), whose sum is σ = 185292656. Its totient is φ = 92646324.

The previous prime is 138969449. The next prime is 138969491. The reversal of 138969489 is 984969831.

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: 984969831 = 3 ⋅328323277.

It is not a de Polignac number, because 138969489 - 2⁷ = 138969361 is a prime.

It is a super-2 number, since 2×138969489² = 38625037745842242, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (138969419) 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, 23161579 + ... + 23161584.

It is an arithmetic number, because the mean of its divisors is an integer number (46323164).

Almost surely, 2^138969489 is an apocalyptic number.

It is an amenable number.

138969489 is a deficient number, since it is larger than the sum of its proper divisors (46323167).

138969489 is an equidigital number, since it uses as much as digits as its factorization.

138969489 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 46323166.

The product of its digits is 3359232, while the sum is 57.

The square root of 138969489 is about 11788.5320969152. The cubic root of 138969489 is about 517.9722422677.

The spelling of 138969489 in words is "one hundred thirty-eight million, nine hundred sixty-nine thousand, four hundred eighty-nine".