1585840 has 40 divisors (see below), whose sum is σ = 3781008. Its totient is φ = 618240.

The previous prime is 1585819. The next prime is 1585889. The reversal of 1585840 is 485851.

It is a tau number, because it is divible by the number of its divisors (40).

It is a Smith number, since the sum of its digits (31) coincides with the sum of the digits of its prime factors.

It is an Ulam number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 3210 + ... + 3670.

2^1585840 is an apocalyptic number.

1585840 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 1585840, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1890504).

1585840 is an abundant number, since it is smaller than the sum of its proper divisors (2195168).

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

1585840 is a wasteful number, since it uses less digits than its factorization.

1585840 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 517 (or 511 counting only the distinct ones).

The product of its (nonzero) digits is 6400, while the sum is 31.

The square root of 1585840 is about 1259.3013936306. The cubic root of 1585840 is about 116.6146525507.

The spelling of 1585840 in words is "one million, five hundred eighty-five thousand, eight hundred forty".