138788437 has 4 divisors (see below), whose sum is σ = 138825676. Its totient is φ = 138751200.

The previous prime is 138788413. The next prime is 138788449. The reversal of 138788437 is 734887831.

138788437 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 an emirpimes, since its reverse is a distinct semiprime: 734887831 = 1123 ⋅654397.

It can be written as a sum of positive squares in 2 ways, for example, as 2692881 + 136095556 = 1641^2 + 11666^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-138788437 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (138788467) 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, 12318 + ... + 20719.

It is an arithmetic number, because the mean of its divisors is an integer number (34706419).

Almost surely, 2^138788437 is an apocalyptic number.

It is an amenable number.

138788437 is a deficient number, since it is larger than the sum of its proper divisors (37239).

138788437 is an equidigital number, since it uses as much as digits as its factorization.

138788437 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 37238.

The product of its digits is 903168, while the sum is 49.

The square root of 138788437 is about 11780.8504361952. The cubic root of 138788437 is about 517.7472032641.

The spelling of 138788437 in words is "one hundred thirty-eight million, seven hundred eighty-eight thousand, four hundred thirty-seven".