1801543666 has 16 divisors (see below), whose sum is σ = 2939003928. Its totient is φ = 823248000.

The previous prime is 1801543661. The next prime is 1801543717. The reversal of 1801543666 is 6663451081.

It can be written as a sum of positive squares in 4 ways, for example, as 1119237025 + 682306641 = 33455^2 + 26121^2 .

It is not an unprimeable number, because it can be changed into a prime (1801543661) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 340395 + ... + 345646.

Almost surely, 2^1801543666 is an apocalyptic number.

1801543666 is a deficient number, since it is larger than the sum of its proper divisors (1137460262).

1801543666 is a wasteful number, since it uses less digits than its factorization.

1801543666 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 686157.

The product of its (nonzero) digits is 103680, while the sum is 40.

The square root of 1801543666 is about 42444.5952507501. The cubic root of 1801543666 is about 1216.7880363650.

The spelling of 1801543666 in words is "one billion, eight hundred one million, five hundred forty-three thousand, six hundred sixty-six".