138782321721166 has 64 divisors (see below), whose sum is σ = 226610369979840. Its totient is φ = 63706851486720.

The previous prime is 138782321721157. The next prime is 138782321721167. The reversal of 138782321721166 is 661127123287831.

It is a self number, because there is not a number n which added to its sum of digits gives 138782321721166.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (138782321721167) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 3163684765 + ... + 3163728631.

It is an arithmetic number, because the mean of its divisors is an integer number (3540787030935).

Almost surely, 2^{138782321721166} is an apocalyptic number.

138782321721166 is a deficient number, since it is larger than the sum of its proper divisors (87828048258674).

138782321721166 is an equidigital number, since it uses as much as digits as its factorization.

138782321721166 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 51814 (or 51780 counting only the distinct ones).

The product of its digits is 8128512, while the sum is 58.

The spelling of 138782321721166 in words is "one hundred thirty-eight trillion, seven hundred eighty-two billion, three hundred twenty-one million, seven hundred twenty-one thousand, one hundred sixty-six".