138236437 has 4 divisors (see below), whose sum is σ = 138287776. Its totient is φ = 138185100.

The previous prime is 138236429. The next prime is 138236467. The reversal of 138236437 is 734632831.

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.

It is a cyclic number.

It is not a de Polignac number, because 138236437 - 2³ = 138236429 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 138236396 and 138236405.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (138236467) 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, 21393 + ... + 27094.

It is an arithmetic number, because the mean of its divisors is an integer number (34571944).

Almost surely, 2^138236437 is an apocalyptic number.

It is an amenable number.

138236437 is a deficient number, since it is larger than the sum of its proper divisors (51339).

138236437 is an equidigital number, since it uses as much as digits as its factorization.

138236437 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 51338.

The product of its digits is 72576, while the sum is 37.

The square root of 138236437 is about 11757.3992447310. The cubic root of 138236437 is about 517.0598832947.

The spelling of 138236437 in words is "one hundred thirty-eight million, two hundred thirty-six thousand, four hundred thirty-seven".