1663891606 has 16 divisors (see below), whose sum is σ = 2689296624. Its totient is φ = 767529504.

The previous prime is 1663891597. The next prime is 1663891631. The reversal of 1663891606 is 6061983661.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 33705 + ... + 66811.

It is an arithmetic number, because the mean of its divisors is an integer number (168081039).

Almost surely, 2^1663891606 is an apocalyptic number.

1663891606 is a deficient number, since it is larger than the sum of its proper divisors (1025405018).

1663891606 is a wasteful number, since it uses less digits than its factorization.

1663891606 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 35055.

The product of its (nonzero) digits is 279936, while the sum is 46.

The square root of 1663891606 is about 40790.8274738329. The cubic root of 1663891606 is about 1184.9726962915.

The spelling of 1663891606 in words is "one billion, six hundred sixty-three million, eight hundred ninety-one thousand, six hundred six".