406240 has 24 divisors (see below), whose sum is σ = 960120. Its totient is φ = 162432.

The previous prime is 406207. The next prime is 406247. The reversal of 406240 is 42604.

406240 = 46² + 47² + ... + 109².

It is a Harshad number since it is a multiple of its sum of digits (16).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (406247) 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, 1110 + ... + 1429.

It is an arithmetic number, because the mean of its divisors is an integer number (40005).

2⁴⁰⁶²⁴⁰ is an apocalyptic number.

406240 is a gapful number since it is divisible by the number (40) formed by its first and last digit.

It is an amenable number.

406240 is an abundant number, since it is smaller than the sum of its proper divisors (553880).

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

406240 is a wasteful number, since it uses less digits than its factorization.

406240 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2554 (or 2546 counting only the distinct ones).

The product of its (nonzero) digits is 192, while the sum is 16.

The square root of 406240 is about 637.3695945054. The cubic root of 406240 is about 74.0617940137.

Adding to 406240 its reverse (42604), we get a palindrome (448844).

It can be divided in two parts, 406 and 240, that added together give a palindrome (646).

The spelling of 406240 in words is "four hundred six thousand, two hundred forty".