1666638018244 has 12 divisors (see below), whose sum is σ = 2929134201084. Its totient is φ = 829742532224.

The previous prime is 1666638018203. The next prime is 1666638018263. The reversal of 1666638018244 is 4428108366661.

It is a happy number.

It can be written as a sum of positive squares in 2 ways, for example, as 469937670400 + 1196700347844 = 685520^2 + 1093938^2 .

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 894118177 + ... + 894120040.

It is an arithmetic number, because the mean of its divisors is an integer number (244094516757).

Almost surely, 2^{1666638018244} is an apocalyptic number.

It is an amenable number.

1666638018244 is a deficient number, since it is larger than the sum of its proper divisors (1262496182840).

1666638018244 is a wasteful number, since it uses less digits than its factorization.

1666638018244 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1788238454 (or 1788238452 counting only the distinct ones).

The product of its (nonzero) digits is 7962624, while the sum is 55.

The spelling of 1666638018244 in words is "one trillion, six hundred sixty-six billion, six hundred thirty-eight million, eighteen thousand, two hundred forty-four".