139644666 has 48 divisors (see below), whose sum is σ = 350188800. Its totient is φ = 39390624.

The previous prime is 139644643. The next prime is 139644671. The reversal of 139644666 is 666446931.

It is a Curzon number.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 2940 + ... + 16968.

It is an arithmetic number, because the mean of its divisors is an integer number (7295600).

Almost surely, 2^139644666 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 139644666, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (175094400).

139644666 is an abundant number, since it is smaller than the sum of its proper divisors (210544134).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

139644666 is a wasteful number, since it uses less digits than its factorization.

139644666 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 14123 (or 14120 counting only the distinct ones).

The product of its digits is 559872, while the sum is 45.

The square root of 139644666 is about 11817.1344242164. The cubic root of 139644666 is about 518.8097356864.

The spelling of 139644666 in words is "one hundred thirty-nine million, six hundred forty-four thousand, six hundred sixty-six".