405040240 has 60 divisors (see below), whose sum is σ = 1035136872. Its totient is φ = 147283840.

The previous prime is 405040217. The next prime is 405040241. The reversal of 405040240 is 42040504.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (405040241) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 11242 + ... + 30601.

Almost surely, 2^405040240 is an apocalyptic number.

405040240 is a gapful number since it is divisible by the number (40) formed by its first and last digit.

It is an amenable number.

405040240 is an abundant number, since it is smaller than the sum of its proper divisors (630096632).

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

405040240 is a wasteful number, since it uses less digits than its factorization.

405040240 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 41878 (or 41861 counting only the distinct ones).

The product of its (nonzero) digits is 640, while the sum is 19.

The square root of 405040240 is about 20125.6115435035. The cubic root of 405040240 is about 739.8881252837. Note that the first 3 decimals are identical.

Adding to 405040240 its reverse (42040504), we get a palindrome (447080744).

The spelling of 405040240 in words is "four hundred five million, forty thousand, two hundred forty".