138658237 has 4 divisors (see below), whose sum is σ = 144686880. Its totient is φ = 132629596.

The previous prime is 138658231. The next prime is 138658241. The reversal of 138658237 is 732856831.

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 138658237 - 2⁷ = 138658109 is a prime.

It is a super-2 number, since 2×138658237² = 38452213375896338, which contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 138658193 and 138658202.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (138658231) 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 3 ways as a sum of consecutive naturals, for example, 3014287 + ... + 3014332.

It is an arithmetic number, because the mean of its divisors is an integer number (36171720).

Almost surely, 2^138658237 is an apocalyptic number.

It is an amenable number.

138658237 is a deficient number, since it is larger than the sum of its proper divisors (6028643).

138658237 is an equidigital number, since it uses as much as digits as its factorization.

138658237 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6028642.

The product of its digits is 241920, while the sum is 43.

The square root of 138658237 is about 11775.3232227400. The cubic root of 138658237 is about 517.5852498669.

The spelling of 138658237 in words is "one hundred thirty-eight million, six hundred fifty-eight thousand, two hundred thirty-seven".