407840 has 24 divisors (see below), whose sum is σ = 963900. Its totient is φ = 163072.

The previous prime is 407833. The next prime is 407843. The reversal of 407840 is 48704.

407840 is digitally balanced in base 3, because in such base it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in 2 ways, for example, as 394384 + 13456 = 628^2 + 116^2 .

It is not an unprimeable number, because it can be changed into a prime (407843) by changing a digit.

407840 is an untouchable number, because it is not equal to the sum of proper divisors of any number.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1115 + ... + 1434.

2⁴⁰⁷⁸⁴⁰ is an apocalyptic number.

407840 is a gapful number since it is divisible by the number (40) formed by its first and last digit.

It is an amenable number.

407840 is an abundant number, since it is smaller than the sum of its proper divisors (556060).

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

407840 is a wasteful number, since it uses less digits than its factorization.

407840 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2564 (or 2556 counting only the distinct ones).

The product of its (nonzero) digits is 896, while the sum is 23.

The square root of 407840 is about 638.6235197673. The cubic root of 407840 is about 74.1588988765.

It can be divided in two parts, 40 and 7840, that multiplied together give a square (313600 = 560²).

The spelling of 407840 in words is "four hundred seven thousand, eight hundred forty".