1665331681686 has 32 divisors (see below), whose sum is σ = 3526647608160. Its totient is φ = 522447684096.

The previous prime is 1665331681679. The next prime is 1665331681691. The reversal of 1665331681686 is 6861861335661.

It is a super-2 number, since 2×1665331681686² (a number of 25 digits) contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 7631040 + ... + 7846236.

It is an arithmetic number, because the mean of its divisors is an integer number (110207737755).

Almost surely, 2^{1665331681686} is an apocalyptic number.

1665331681686 is an abundant number, since it is smaller than the sum of its proper divisors (1861315926474).

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

1665331681686 is a wasteful number, since it uses less digits than its factorization.

1665331681686 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 291088.

The product of its digits is 22394880, while the sum is 60.

The spelling of 1665331681686 in words is "one trillion, six hundred sixty-five billion, three hundred thirty-one million, six hundred eighty-one thousand, six hundred eighty-six".