1666556564 has 12 divisors (see below), whose sum is σ = 2920699488. Its totient is φ = 832071000.

The previous prime is 1666556537. The next prime is 1666556569. The reversal of 1666556564 is 4656556661.

It is a super-2 number, since 2×1666556564² = 5554821562022972192, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1666556569) 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, 298712 + ... + 304239.

It is an arithmetic number, because the mean of its divisors is an integer number (243391624).

Almost surely, 2^1666556564 is an apocalyptic number.

It is an amenable number.

1666556564 is a deficient number, since it is larger than the sum of its proper divisors (1254142924).

1666556564 is a wasteful number, since it uses less digits than its factorization.

1666556564 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 603646 (or 603644 counting only the distinct ones).

The product of its digits is 3888000, while the sum is 50.

The square root of 1666556564 is about 40823.4805473517. The cubic root of 1666556564 is about 1185.6049926926.

The spelling of 1666556564 in words is "one billion, six hundred sixty-six million, five hundred fifty-six thousand, five hundred sixty-four".