405340240 has 20 divisors (see below), whose sum is σ = 942416244. Its totient is φ = 162136064.

The previous prime is 405340223. The next prime is 405340241. The reversal of 405340240 is 42043504.

It is a happy number.

It can be written as a sum of positive squares in 2 ways, for example, as 70157376 + 335182864 = 8376^2 + 18308^2 .

It is a tau number, because it is divible by the number of its divisors (20).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (405340241) by changing a digit.

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, 2533297 + ... + 2533456.

Almost surely, 2^405340240 is an apocalyptic number.

405340240 is a gapful number since it is divisible by the number (40) formed by its first and last digit.

It is an amenable number.

405340240 is an abundant number, since it is smaller than the sum of its proper divisors (537076004).

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

405340240 is a wasteful number, since it uses less digits than its factorization.

405340240 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5066766 (or 5066760 counting only the distinct ones).

The product of its (nonzero) digits is 1920, while the sum is 22.

The square root of 405340240 is about 20133.0633535982. The cubic root of 405340240 is about 740.0707504791.

Adding to 405340240 its reverse (42043504), we get a palindrome (447383744).

The spelling of 405340240 in words is "four hundred five million, three hundred forty thousand, two hundred forty".