138538507 has 2 divisors, whose sum is σ = 138538508. Its totient is φ = 138538506.

The previous prime is 138538487. The next prime is 138538511. The reversal of 138538507 is 705835831.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 138538507 - 2¹¹ = 138536459 is a prime.

It is a Chen prime.

It is a self number, because there is not a number n which added to its sum of digits gives 138538507.

It is not a weakly prime, because it can be changed into another prime (138538567) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 69269253 + 69269254.

It is an arithmetic number, because the mean of its divisors is an integer number (69269254).

Almost surely, 2^138538507 is an apocalyptic number.

138538507 is a deficient number, since it is larger than the sum of its proper divisors (1).

138538507 is an equidigital number, since it uses as much as digits as its factorization.

138538507 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 100800, while the sum is 40.

The square root of 138538507 is about 11770.2381879043. The cubic root of 138538507 is about 517.4362304053.

The spelling of 138538507 in words is "one hundred thirty-eight million, five hundred thirty-eight thousand, five hundred seven".