138897866 has 16 divisors (see below), whose sum is σ = 219557760. Its totient is φ = 65720160.

The previous prime is 138897853. The next prime is 138897883. The reversal of 138897866 is 668798831.

It is a happy number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 48815 + ... + 51581.

It is an arithmetic number, because the mean of its divisors is an integer number (13722360).

Almost surely, 2^138897866 is an apocalyptic number.

138897866 is a deficient number, since it is larger than the sum of its proper divisors (80659894).

138897866 is a wasteful number, since it uses less digits than its factorization.

138897866 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4109.

The product of its digits is 3483648, while the sum is 56.

The square root of 138897866 is about 11785.4938801902. The cubic root of 138897866 is about 517.8832416738.

The spelling of 138897866 in words is "one hundred thirty-eight million, eight hundred ninety-seven thousand, eight hundred sixty-six".