1285000000 has 112 divisors (see below), whose sum is σ = 3199796496. Its totient is φ = 512000000.

The previous prime is 1284999979. The next prime is 1285000033. The reversal of 1285000000 is 5821.

It is a happy number.

It can be written as a sum of positive squares in 8 ways, for example, as 1249763904 + 35236096 = 35352^2 + 5936^2 .

It is a Harshad number since it is a multiple of its sum of digits (16).

It is a congruent number.

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 15 ways as a sum of consecutive naturals, for example, 4999872 + ... + 5000128.

Almost surely, 2^1285000000 is an apocalyptic number.

1285000000 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 1285000000, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1599898248).

1285000000 is an abundant number, since it is smaller than the sum of its proper divisors (1914796496).

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

1285000000 is an frugal number, since it uses more digits than its factorization.

1285000000 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 304 (or 264 counting only the distinct ones).

The product of its (nonzero) digits is 80, while the sum is 16.

The square root of 1285000000 is about 35846.8966578698. The cubic root of 1285000000 is about 1087.1789689655.

Adding to 1285000000 its reverse (5821), we get a palindrome (1285005821).

The spelling of 1285000000 in words is "one billion, two hundred eighty-five million", and thus it is an aban number.