138247237 has 2 divisors, whose sum is σ = 138247238. Its totient is φ = 138247236.

The previous prime is 138247199. The next prime is 138247243. The reversal of 138247237 is 732742831.

138247237 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 108805761 + 29441476 = 10431^2 + 5426^2 .

It is a cyclic number.

It is not a de Polignac number, because 138247237 - 2¹⁵ = 138214469 is a prime.

It is a super-2 number, since 2×138247237² = 38224597076268338, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 138247196 and 138247205.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (138247937) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 69123618 + 69123619.

It is an arithmetic number, because the mean of its divisors is an integer number (69123619).

Almost surely, 2^138247237 is an apocalyptic number.

It is an amenable number.

138247237 is a deficient number, since it is larger than the sum of its proper divisors (1).

138247237 is an equidigital number, since it uses as much as digits as its factorization.

138247237 is an evil number, because the sum of its binary digits is even.

The product of its digits is 56448, while the sum is 37.

The square root of 138247237 is about 11757.8585210063. The cubic root of 138247237 is about 517.0733483922.

The spelling of 138247237 in words is "one hundred thirty-eight million, two hundred forty-seven thousand, two hundred thirty-seven".