1285850640 has 160 divisors (see below), whose sum is σ = 4142413440. Its totient is φ = 329674752.

The previous prime is 1285850623. The next prime is 1285850647. The reversal of 1285850640 is 460585821.

It is not an unprimeable number, because it can be changed into a prime (1285850647) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 789507 + ... + 791133.

It is an arithmetic number, because the mean of its divisors is an integer number (25890084).

Almost surely, 2^1285850640 is an apocalyptic number.

1285850640 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 1285850640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2071206720).

1285850640 is an abundant number, since it is smaller than the sum of its proper divisors (2856562800).

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

1285850640 is a wasteful number, since it uses less digits than its factorization.

1285850640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1769 (or 1763 counting only the distinct ones).

The product of its (nonzero) digits is 76800, while the sum is 39.

The square root of 1285850640 is about 35858.7595992946. The cubic root of 1285850640 is about 1087.4188117485.

The spelling of 1285850640 in words is "one billion, two hundred eighty-five million, eight hundred fifty thousand, six hundred forty".