1666663663 has 16 divisors (see below), whose sum is σ = 2059720704. Its totient is φ = 1315923840.

The previous prime is 1666663643. The next prime is 1666663673. The reversal of 1666663663 is 3663666661.

It is not a de Polignac number, because 1666663663 - 2⁹ = 1666663151 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1666663643) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 143403 + ... + 154588.

It is an arithmetic number, because the mean of its divisors is an integer number (128732544).

Almost surely, 2^1666663663 is an apocalyptic number.

1666663663 is a deficient number, since it is larger than the sum of its proper divisors (393057041).

1666663663 is a wasteful number, since it uses less digits than its factorization.

1666663663 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 298062.

The product of its digits is 2519424, while the sum is 49.

The square root of 1666663663 is about 40824.7922591163. The cubic root of 1666663663 is about 1185.6303892481.

The spelling of 1666663663 in words is "one billion, six hundred sixty-six million, six hundred sixty-three thousand, six hundred sixty-three".