1646681666812 has 96 divisors (see below), whose sum is σ = 3820190528000. Its totient is φ = 602796079872.

The previous prime is 1646681666809. The next prime is 1646681666881. The reversal of 1646681666812 is 2186661866461.

It is a happy number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 2471187 + ... + 3065962.

Almost surely, 2^{1646681666812} is an apocalyptic number.

It is an amenable number.

1646681666812 is an abundant number, since it is smaller than the sum of its proper divisors (2173508861188).

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

1646681666812 is a wasteful number, since it uses less digits than its factorization.

1646681666812 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5537235 (or 5537233 counting only the distinct ones).

The product of its digits is 23887872, while the sum is 61.

The spelling of 1646681666812 in words is "one trillion, six hundred forty-six billion, six hundred eighty-one million, six hundred sixty-six thousand, eight hundred twelve".