307840 has 64 divisors (see below), whose sum is σ = 813960. Its totient is φ = 110592.

The previous prime is 307831. The next prime is 307843. The reversal of 307840 is 48703.

307840 = T₆₃ + T₆₄ + ... + T₁₂₇.

It can be written as a sum of positive squares in 4 ways, for example, as 254016 + 53824 = 504^2 + 232^2 .

It is a tau number, because it is divible by the number of its divisors (64).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (307843) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 8302 + ... + 8338.

2³⁰⁷⁸⁴⁰ is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 307840, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (406980).

307840 is an abundant number, since it is smaller than the sum of its proper divisors (506120).

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

307840 is a wasteful number, since it uses less digits than its factorization.

307840 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 69 (or 57 counting only the distinct ones).

The product of its (nonzero) digits is 672, while the sum is 22.

The square root of 307840 is about 554.8333083008. The cubic root of 307840 is about 67.5214380922.

The spelling of 307840 in words is "three hundred seven thousand, eight hundred forty".