1591640 has 16 divisors (see below), whose sum is σ = 3581280. Its totient is φ = 636640.

The previous prime is 1591637. The next prime is 1591663. The reversal of 1591640 is 461951.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 19856 + ... + 19935.

It is an arithmetic number, because the mean of its divisors is an integer number (223830).

2^1591640 is an apocalyptic number.

1591640 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1591640 is an abundant number, since it is smaller than the sum of its proper divisors (1989640).

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

1591640 is a wasteful number, since it uses less digits than its factorization.

1591640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 39802 (or 39798 counting only the distinct ones).

The product of its (nonzero) digits is 1080, while the sum is 26.

The square root of 1591640 is about 1261.6021559905. The cubic root of 1591640 is about 116.7566471370.

The spelling of 1591640 in words is "one million, five hundred ninety-one thousand, six hundred forty".