405240 has 64 divisors (see below), whose sum is σ = 1330560. Its totient is φ = 97920.
The previous prime is 405239. The next prime is 405241. The reversal of 405240 is 42504.
405240 is nontrivially palindromic in base 14.
It is an interprime number because it is at equal distance from previous prime (405239) and next prime (405241).
It is a Harshad number since it is a multiple of its sum of digits (15).
It is a congruent number.
It is not an unprimeable number, because it can be changed into a prime (405241) 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 15 ways as a sum of consecutive naturals, for example, 1167 + ... + 1473.
It is an arithmetic number, because the mean of its divisors is an integer number (20790).
2405240 is an apocalyptic number.
405240 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 405240, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (665280).
405240 is an abundant number, since it is smaller than the sum of its proper divisors (925320).
It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.
405240 is a wasteful number, since it uses less digits than its factorization.
405240 is an odious number, because the sum of its binary digits is odd.
The sum of its prime factors is 332 (or 328 counting only the distinct ones).
The product of its (nonzero) digits is 160, while the sum is 15.
The square root of 405240 is about 636.5846369494. The cubic root of 405240 is about 74.0009739341. Note that the first 3 decimals are identical.
Adding to 405240 its reverse (42504), we get a palindrome (447744).
The spelling of 405240 in words is "four hundred five thousand, two hundred forty".
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