1285633881 has 24 divisors (see below), whose sum is σ = 2129172864. Its totient is φ = 732274560.

The previous prime is 1285633873. The next prime is 1285633939. The reversal of 1285633881 is 1883365821.

1285633881 is a `hidden beast` number, since 1 + 2 + 8 + 5 + 633 + 8 + 8 + 1 = 666.

It is not a de Polignac number, because 1285633881 - 2³ = 1285633873 is a prime.

It is a super-2 number, since 2×1285633881² = 3305708951950244322, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (1285633801) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 13216 + ... + 52401.

It is an arithmetic number, because the mean of its divisors is an integer number (88715536).

Almost surely, 2^1285633881 is an apocalyptic number.

It is an amenable number.

1285633881 is a deficient number, since it is larger than the sum of its proper divisors (843538983).

1285633881 is a wasteful number, since it uses less digits than its factorization.

1285633881 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 65941 (or 65938 counting only the distinct ones).

The product of its digits is 276480, while the sum is 45.

The square root of 1285633881 is about 35855.7370723292. The cubic root of 1285633881 is about 1087.3577053616.

The spelling of 1285633881 in words is "one billion, two hundred eighty-five million, six hundred thirty-three thousand, eight hundred eighty-one".