1305840 has 40 divisors (see below), whose sum is σ = 4048848. Its totient is φ = 348160.

The previous prime is 1305823. The next prime is 1305869. The reversal of 1305840 is 485031.

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

It is a congruent 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, 2481 + ... + 2960.

2^1305840 is an apocalyptic number.

1305840 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1305840 is an abundant number, since it is smaller than the sum of its proper divisors (2743008).

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

1305840 is a wasteful number, since it uses less digits than its factorization.

1305840 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5457 (or 5451 counting only the distinct ones).

The product of its (nonzero) digits is 480, while the sum is 21.

The square root of 1305840 is about 1142.7335647473. The cubic root of 1305840 is about 109.3024732786.

It can be divided in two parts, 1305 and 840, that added together give a triangular number (2145 = T₆₅).

The spelling of 1305840 in words is "one million, three hundred five thousand, eight hundred forty".