138866571 has 12 divisors (see below), whose sum is σ = 209306448. Its totient is φ = 88552464.

The previous prime is 138866551. The next prime is 138866599. The reversal of 138866571 is 175668831.

138866571 is a `hidden beast` number, since 13 + 8 + 8 + 66 + 571 = 666.

It is not a de Polignac number, because 138866571 - 2⁷ = 138866443 is a prime.

It is not an unprimeable number, because it can be changed into a prime (138866521) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 335220 + ... + 335633.

It is an arithmetic number, because the mean of its divisors is an integer number (17442204).

Almost surely, 2^138866571 is an apocalyptic number.

138866571 is a deficient number, since it is larger than the sum of its proper divisors (70439877).

138866571 is a wasteful number, since it uses less digits than its factorization.

138866571 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 670882 (or 670879 counting only the distinct ones).

The product of its digits is 241920, while the sum is 45.

The square root of 138866571 is about 11784.1661139005. The cubic root of 138866571 is about 517.8443440918.

The spelling of 138866571 in words is "one hundred thirty-eight million, eight hundred sixty-six thousand, five hundred seventy-one".