1289996660 has 24 divisors (see below), whose sum is σ = 2710077216. Its totient is φ = 515792160.

The previous prime is 1289996641. The next prime is 1289996683. The reversal of 1289996660 is 666999821.

It is a super-2 number, since 2×1289996660² = 3328182765622311200, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 1289996596 and 1289996605.

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, 44555 + ... + 67565.

It is an arithmetic number, because the mean of its divisors is an integer number (112919884).

Almost surely, 2^1289996660 is an apocalyptic number.

1289996660 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1289996660 is an abundant number, since it is smaller than the sum of its proper divisors (1420080556).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

1289996660 is a wasteful number, since it uses less digits than its factorization.

1289996660 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 25823 (or 25821 counting only the distinct ones).

The product of its (nonzero) digits is 2519424, while the sum is 56.

The square root of 1289996660 is about 35916.5234954610. The cubic root of 1289996660 is about 1088.5862939479.

The spelling of 1289996660 in words is "one billion, two hundred eighty-nine million, nine hundred ninety-six thousand, six hundred sixty".