405400320 has 216 divisors, whose sum is σ = 1511096496. Its totient is φ = 99753984.

The previous prime is 405400313. The next prime is 405400351. The reversal of 405400320 is 23004504.

It is a happy number.

It is a super-2 number, since 2×405400320² = 328698838912204800, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (18).

It is a junction number, because it is equal to n+sod(n) for n = 405400293 and 405400302.

It is an unprimeable number.

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 23 ways as a sum of consecutive naturals, for example, 148407 + ... + 151113.

Almost surely, 2^405400320 is an apocalyptic number.

405400320 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 405400320, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (755548248).

405400320 is an abundant number, since it is smaller than the sum of its proper divisors (1105696176).

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

405400320 is a wasteful number, since it uses less digits than its factorization.

405400320 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2747 (or 2730 counting only the distinct ones).

The product of its (nonzero) digits is 480, while the sum is 18.

The square root of 405400320 is about 20134.5553713013. Note that the first 3 decimals coincide. The cubic root of 405400320 is about 740.1073133874.

Adding to 405400320 its reverse (23004504), we get a palindrome (428404824).

The spelling of 405400320 in words is "four hundred five million, four hundred thousand, three hundred twenty".