1663639706 has 8 divisors (see below), whose sum is σ = 2504341044. Its totient is φ = 828859360.

The previous prime is 1663639699. The next prime is 1663639717. The reversal of 1663639706 is 6079363661.

It is a happy number.

It can be written as a sum of positive squares in 2 ways, for example, as 1532331025 + 131308681 = 39145^2 + 11459^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1479545 + ... + 1480668.

Almost surely, 2^1663639706 is an apocalyptic number.

1663639706 is a deficient number, since it is larger than the sum of its proper divisors (840701338).

1663639706 is a wasteful number, since it uses less digits than its factorization.

1663639706 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2960496.

The product of its (nonzero) digits is 734832, while the sum is 47.

The square root of 1663639706 is about 40787.7396529889. The cubic root of 1663639706 is about 1184.9128947825.

The spelling of 1663639706 in words is "one billion, six hundred sixty-three million, six hundred thirty-nine thousand, seven hundred six".