138355237 has 4 divisors (see below), whose sum is σ = 138418380. Its totient is φ = 138292096.

The previous prime is 138355229. The next prime is 138355249. The reversal of 138355237 is 732553831.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 113763556 + 24591681 = 10666^2 + 4959^2 .

It is a cyclic number.

It is not a de Polignac number, because 138355237 - 2³ = 138355229 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 138355196 and 138355205.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (138355337) 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, 28162 + ... + 32707.

It is an arithmetic number, because the mean of its divisors is an integer number (34604595).

Almost surely, 2^138355237 is an apocalyptic number.

It is an amenable number.

138355237 is a deficient number, since it is larger than the sum of its proper divisors (63143).

138355237 is an equidigital number, since it uses as much as digits as its factorization.

138355237 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 63142.

The product of its digits is 75600, while the sum is 37.

The square root of 138355237 is about 11762.4502974508. The cubic root of 138355237 is about 517.2079608137.

The spelling of 138355237 in words is "one hundred thirty-eight million, three hundred fifty-five thousand, two hundred thirty-seven".