1285683840 has 384 divisors, whose sum is σ = 5266235520. Its totient is φ = 293621760.

The previous prime is 1285683823. The next prime is 1285683869. The reversal of 1285683840 is 483865821.

1285683840 is a `hidden beast` number, since 1 + 2 + 8 + 568 + 3 + 84 + 0 = 666.

It is a tau number, because it is divible by the number of its divisors (384).

It is a Harshad number since it is a multiple of its sum of digits (45).

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 1088050 + ... + 1089230.

It is an arithmetic number, because the mean of its divisors is an integer number (13714155).

Almost surely, 2^1285683840 is an apocalyptic number.

1285683840 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 1285683840, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2633117760).

1285683840 is an abundant number, since it is smaller than the sum of its proper divisors (3980551680).

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

1285683840 is an equidigital number, since it uses as much as digits as its factorization.

1285683840 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1222 (or 1198 counting only the distinct ones).

The product of its (nonzero) digits is 368640, while the sum is 45.

The square root of 1285683840 is about 35856.4337323164. The cubic root of 1285683840 is about 1087.3717898794.

The spelling of 1285683840 in words is "one billion, two hundred eighty-five million, six hundred eighty-three thousand, eight hundred forty".