1665669663 has 40 divisors (see below), whose sum is σ = 2920576032. Its totient is φ = 926074944.

The previous prime is 1665669619. The next prime is 1665669671. The reversal of 1665669663 is 3669665661.

1665669663 is a `hidden beast` number, since 16 + 6 + 566 + 9 + 6 + 63 = 666.

It is not a de Polignac number, because 1665669663 - 2⁹ = 1665669151 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1661669663) by changing a digit.

It is a polite number, since it can be written in 39 ways as a sum of consecutive naturals, for example, 18720 + ... + 60677.

Almost surely, 2^1665669663 is an apocalyptic number.

1665669663 is a deficient number, since it is larger than the sum of its proper divisors (1254906369).

1665669663 is an equidigital number, since it uses as much as digits as its factorization.

1665669663 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 79453 (or 79444 counting only the distinct ones).

The product of its digits is 6298560, while the sum is 54.

The square root of 1665669663 is about 40812.6164684402. The cubic root of 1665669663 is about 1185.3946386284.

The spelling of 1665669663 in words is "one billion, six hundred sixty-five million, six hundred sixty-nine thousand, six hundred sixty-three".