1285136856 has 96 divisors (see below), whose sum is σ = 3618903600. Its totient is φ = 411505920.

The previous prime is 1285136843. The next prime is 1285136861. The reversal of 1285136856 is 6586315821.

1285136856 is a `hidden beast` number, since 1 + 28 + 513 + 68 + 56 = 666.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 439110 + ... + 442026.

Almost surely, 2^1285136856 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 1285136856, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1809451800).

1285136856 is an abundant number, since it is smaller than the sum of its proper divisors (2333766744).

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

1285136856 is a wasteful number, since it uses less digits than its factorization.

1285136856 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3169 (or 3162 counting only the distinct ones).

The product of its digits is 345600, while the sum is 45.

The square root of 1285136856 is about 35848.8055031127. The cubic root of 1285136856 is about 1087.2175634359.

The spelling of 1285136856 in words is "one billion, two hundred eighty-five million, one hundred thirty-six thousand, eight hundred fifty-six".