138634487 has 2 divisors, whose sum is σ = 138634488. Its totient is φ = 138634486.

The previous prime is 138634421. The next prime is 138634553. The reversal of 138634487 is 784436831.

138634487 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a balanced prime because it is at equal distance from previous prime (138634421) and next prime (138634553).

It is a cyclic number.

It is not a de Polignac number, because 138634487 - 2¹⁰ = 138633463 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (138634187) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 69317243 + 69317244.

It is an arithmetic number, because the mean of its divisors is an integer number (69317244).

Almost surely, 2^138634487 is an apocalyptic number.

138634487 is a deficient number, since it is larger than the sum of its proper divisors (1).

138634487 is an equidigital number, since it uses as much as digits as its factorization.

138634487 is an evil number, because the sum of its binary digits is even.

The product of its digits is 387072, while the sum is 44.

The square root of 138634487 is about 11774.3147146660. The cubic root of 138634487 is about 517.5556967444. Note that the first 3 decimals are identical.

The spelling of 138634487 in words is "one hundred thirty-eight million, six hundred thirty-four thousand, four hundred eighty-seven".