1661616808 has 8 divisors (see below), whose sum is σ = 3115531530. Its totient is φ = 830808400.

The previous prime is 1661616797. The next prime is 1661616821. The reversal of 1661616808 is 8086161661.

It can be written as a sum of positive squares in only one way, i.e., 1100779684 + 560837124 = 33178^2 + 23682^2 .

It is a tau number, because it is divible by the number of its divisors (8).

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 103851043 + ... + 103851058.

Almost surely, 2^1661616808 is an apocalyptic number.

It is an amenable number.

1661616808 is a deficient number, since it is larger than the sum of its proper divisors (1453914722).

1661616808 is a wasteful number, since it uses less digits than its factorization.

1661616808 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 207702107 (or 207702103 counting only the distinct ones).

The product of its (nonzero) digits is 82944, while the sum is 43.

The square root of 1661616808 is about 40762.9342417839. The cubic root of 1661616808 is about 1184.4324361635.

The spelling of 1661616808 in words is "one billion, six hundred sixty-one million, six hundred sixteen thousand, eight hundred eight".