1666681516 has 12 divisors (see below), whose sum is σ = 2931350800. Its totient is φ = 829152720.

The previous prime is 1666681483. The next prime is 1666681519. The reversal of 1666681516 is 6151866661.

It is a hoax number, since the sum of its digits (46) coincides with the sum of the digits of its distinct prime factors.

It is not an unprimeable number, because it can be changed into a prime (1666681519) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1046115 + ... + 1047706.

Almost surely, 2^1666681516 is an apocalyptic number.

It is an amenable number.

1666681516 is a deficient number, since it is larger than the sum of its proper divisors (1264669284).

1666681516 is a wasteful number, since it uses less digits than its factorization.

1666681516 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2094024 (or 2094022 counting only the distinct ones).

The product of its digits is 311040, while the sum is 46.

The square root of 1666681516 is about 40825.0109124296. The cubic root of 1666681516 is about 1185.6346226525.

The spelling of 1666681516 in words is "one billion, six hundred sixty-six million, six hundred eighty-one thousand, five hundred sixteen".