403840 has 32 divisors (see below), whose sum is σ = 966960. Its totient is φ = 161280.

The previous prime is 403831. The next prime is 403849. The reversal of 403840 is 48304.

It is an interprime number because it is at equal distance from previous prime (403831) and next prime (403849).

It is a tau number, because it is divible by the number of its divisors (32).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (403849) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 325 + ... + 955.

2⁴⁰³⁸⁴⁰ is an apocalyptic number.

403840 is a gapful number since it is divisible by the number (40) 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 403840, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (483480).

403840 is an abundant number, since it is smaller than the sum of its proper divisors (563120).

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

403840 is an equidigital number, since it uses as much as digits as its factorization.

403840 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 650 (or 638 counting only the distinct ones).

The product of its (nonzero) digits is 384, while the sum is 19.

The square root of 403840 is about 635.4840674635. The cubic root of 403840 is about 73.9156574974.

The spelling of 403840 in words is "four hundred three thousand, eight hundred forty".