1285633440 has 288 divisors, whose sum is σ = 5400210816. Its totient is φ = 271226880.

The previous prime is 1285633421. The next prime is 1285633451. The reversal of 1285633440 is 443365821.

1285633440 is a `hidden beast` number, since 1 + 28 + 563 + 34 + 40 = 666.

It is a tau number, because it is divible by the number of its divisors (288).

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a junction number, because it is equal to n+sod(n) for n = 1285633395 and 1285633404.

It is an unprimeable number.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 126135 + ... + 135945.

It is an arithmetic number, because the mean of its divisors is an integer number (18750732).

Almost surely, 2^1285633440 is an apocalyptic number.

1285633440 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 1285633440, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2700105408).

1285633440 is an abundant number, since it is smaller than the sum of its proper divisors (4114577376).

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

1285633440 is a wasteful number, since it uses less digits than its factorization.

1285633440 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9852 (or 9841 counting only the distinct ones).

The product of its (nonzero) digits is 69120, while the sum is 36.

The square root of 1285633440 is about 35855.7309226851. The cubic root of 1285633440 is about 1087.3575810325.

The spelling of 1285633440 in words is "one billion, two hundred eighty-five million, six hundred thirty-three thousand, four hundred forty".