138666671 has 16 divisors (see below), whose sum is σ = 172495008. Its totient is φ = 109516800.

The previous prime is 138666659. The next prime is 138666673. The reversal of 138666671 is 176666831.

138666671 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a cyclic number.

It is not a de Polignac number, because 138666671 - 2¹⁸ = 138404527 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 (138666673) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 26090 + ... + 30951.

It is an arithmetic number, because the mean of its divisors is an integer number (10780938).

Almost surely, 2^138666671 is an apocalyptic number.

138666671 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

138666671 is a deficient number, since it is larger than the sum of its proper divisors (33828337).

138666671 is a wasteful number, since it uses less digits than its factorization.

138666671 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 57082.

The product of its digits is 217728, while the sum is 44.

The square root of 138666671 is about 11775.6813390988. The cubic root of 138666671 is about 517.5957438354.

The spelling of 138666671 in words is "one hundred thirty-eight million, six hundred sixty-six thousand, six hundred seventy-one".