1666516556 has 18 divisors (see below), whose sum is σ = 2997365868. Its totient is φ = 810735120.

The previous prime is 1666516541. The next prime is 1666516559. The reversal of 1666516556 is 6556156661.

It is a super-2 number, since 2×1666516556² = 5554554862844202272, which contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 1666516556.

It is not an unprimeable number, because it can be changed into a prime (1666516559) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 146690 + ... + 157641.

It is an arithmetic number, because the mean of its divisors is an integer number (166520326).

Almost surely, 2^1666516556 is an apocalyptic number.

It is an amenable number.

1666516556 is a deficient number, since it is larger than the sum of its proper divisors (1330849312).

1666516556 is a wasteful number, since it uses less digits than its factorization.

1666516556 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 304409 (or 304370 counting only the distinct ones).

The product of its digits is 972000, while the sum is 47.

The square root of 1666516556 is about 40822.9905322969. The cubic root of 1666516556 is about 1185.5955052530.

The spelling of 1666516556 in words is "one billion, six hundred sixty-six million, five hundred sixteen thousand, five hundred fifty-six".