138907287 has 24 divisors (see below), whose sum is σ = 207618320. Its totient is φ = 89424000.

The previous prime is 138907267. The next prime is 138907297. The reversal of 138907287 is 782709831.

138907287 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is not a de Polignac number, because 138907287 - 2⁷ = 138907159 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (138907267) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 44787 + ... + 47787.

Almost surely, 2^138907287 is an apocalyptic number.

138907287 is a deficient number, since it is larger than the sum of its proper divisors (68711033).

138907287 is a wasteful number, since it uses less digits than its factorization.

138907287 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3183 (or 3180 counting only the distinct ones).

The product of its (nonzero) digits is 169344, while the sum is 45.

The square root of 138907287 is about 11785.8935596755. The cubic root of 138907287 is about 517.8949501996.

The spelling of 138907287 in words is "one hundred thirty-eight million, nine hundred seven thousand, two hundred eighty-seven".