138237489 has 32 divisors (see below), whose sum is σ = 233533440. Its totient is φ = 80061696.

The previous prime is 138237479. The next prime is 138237499. The reversal of 138237489 is 984732831.

138237489 is a `hidden beast` number, since 138 + 2 + 37 + 489 = 666.

It is an interprime number because it is at equal distance from previous prime (138237479) and next prime (138237499).

It is not a de Polignac number, because 138237489 - 2⁵ = 138237457 is a prime.

It is not an unprimeable number, because it can be changed into a prime (138237479) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 5617 + ... + 17550.

It is an arithmetic number, because the mean of its divisors is an integer number (7297920).

Almost surely, 2^138237489 is an apocalyptic number.

It is an amenable number.

138237489 is a deficient number, since it is larger than the sum of its proper divisors (95295951).

138237489 is a wasteful number, since it uses less digits than its factorization.

138237489 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 23206 (or 23200 counting only the distinct ones).

The product of its digits is 290304, while the sum is 45.

The square root of 138237489 is about 11757.4439824309. The cubic root of 138237489 is about 517.0611949258.

It can be divided in two parts, 13823 and 7489, that added together give a palindrome (21312).

The spelling of 138237489 in words is "one hundred thirty-eight million, two hundred thirty-seven thousand, four hundred eighty-nine".