1289806664 has 8 divisors (see below), whose sum is σ = 2418387510. Its totient is φ = 644903328.

The previous prime is 1289806657. The next prime is 1289806667. The reversal of 1289806664 is 4666089821.

It is a happy number.

It can be written as a sum of positive squares in only one way, i.e., 1265224900 + 24581764 = 35570^2 + 4958^2 .

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

It is not an unprimeable number, because it can be changed into a prime (1289806667) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 80612909 + ... + 80612924.

Almost surely, 2^1289806664 is an apocalyptic number.

It is an amenable number.

1289806664 is a deficient number, since it is larger than the sum of its proper divisors (1128580846).

1289806664 is a wasteful number, since it uses less digits than its factorization.

1289806664 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 161225839 (or 161225835 counting only the distinct ones).

The product of its (nonzero) digits is 995328, while the sum is 50.

The square root of 1289806664 is about 35913.8784316036. The cubic root of 1289806664 is about 1088.5328475055.

The spelling of 1289806664 in words is "one billion, two hundred eighty-nine million, eight hundred six thousand, six hundred sixty-four".