400005450 has 144 divisors (see below), whose sum is σ = 1170534456. Its totient is φ = 97344000.

The previous prime is 400005449. The next prime is 400005481. The reversal of 400005450 is 54500004.

It is a happy number.

It can be written as a sum of positive squares in 12 ways, for example, as 167107329 + 232898121 = 12927^2 + 15261^2 .

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

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 71 ways as a sum of consecutive naturals, for example, 590512 + ... + 591188.

Almost surely, 2^400005450 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 400005450, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (585267228).

400005450 is an abundant number, since it is smaller than the sum of its proper divisors (770529006).

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

400005450 is a wasteful number, since it uses less digits than its factorization.

400005450 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 809 (or 801 counting only the distinct ones).

The product of its (nonzero) digits is 400, while the sum is 18.

The square root of 400005450 is about 20000.1362495359. The cubic root of 400005450 is about 736.8096460415.

Adding to 400005450 its reverse (54500004), we get a palindrome (454505454).

The spelling of 400005450 in words is "four hundred million, five thousand, four hundred fifty".