1289423872 has 44 divisors (see below), whose sum is σ = 2811939336. Its totient is φ = 586096640.

The previous prime is 1289423851. The next prime is 1289423899. The reversal of 1289423872 is 2783249821.

It is a tau number, because it is divible by the number of its divisors (44).

It is a super-2 number, since 2×1289423872² = 3325227843366944768, which contains 22 as substring.

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 in 3 ways as a sum of consecutive naturals, for example, 45973 + ... + 68500.

Almost surely, 2^1289423872 is an apocalyptic number.

It is an amenable number.

1289423872 is an abundant number, since it is smaller than the sum of its proper divisors (1522515464).

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

1289423872 is a wasteful number, since it uses less digits than its factorization.

1289423872 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 114504 (or 114486 counting only the distinct ones).

The product of its digits is 387072, while the sum is 46.

The square root of 1289423872 is about 35908.5487314650. The cubic root of 1289423872 is about 1088.4251510304.

The spelling of 1289423872 in words is "one billion, two hundred eighty-nine million, four hundred twenty-three thousand, eight hundred seventy-two".