406538240 has 144 divisors (see below), whose sum is σ = 1037099700. Its totient is φ = 152764416.

The previous prime is 406538227. The next prime is 406538291. The reversal of 406538240 is 42835604.

It can be written as a sum of positive squares in 6 ways, for example, as 348046336 + 58491904 = 18656^2 + 7648^2 .

It is a Harshad number since it is a multiple of its sum of digits (32).

It is a junction number, because it is equal to n+sod(n) for n = 406538197 and 406538206.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 10987502 + ... + 10987538.

Almost surely, 2^406538240 is an apocalyptic number.

406538240 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 406538240, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (518549850).

406538240 is an abundant number, since it is smaller than the sum of its proper divisors (630561460).

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

406538240 is an equidigital number, since it uses as much as digits as its factorization.

406538240 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 130 (or 73 counting only the distinct ones).

The product of its (nonzero) digits is 23040, while the sum is 32.

The square root of 406538240 is about 20162.7934572569. The cubic root of 406538240 is about 740.7991366901.

The spelling of 406538240 in words is "four hundred six million, five hundred thirty-eight thousand, two hundred forty".