400423644 has 72 divisors (see below), whose sum is σ = 1094603328. Its totient is φ = 122941440.

The previous prime is 400423601. The next prime is 400423711. The reversal of 400423644 is 446324004.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 21804 + ... + 35724.

It is an arithmetic number, because the mean of its divisors is an integer number (15202824).

Almost surely, 2^400423644 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 400423644, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (547301664).

400423644 is an abundant number, since it is smaller than the sum of its proper divisors (694179684).

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

400423644 is a wasteful number, since it uses less digits than its factorization.

400423644 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 13995 (or 13990 counting only the distinct ones).

The product of its (nonzero) digits is 9216, while the sum is 27.

The square root of 400423644 is about 20010.5882971991. The cubic root of 400423644 is about 737.0663275903.

Adding to 400423644 its reverse (446324004), we get a palindrome (846747648).

The spelling of 400423644 in words is "four hundred million, four hundred twenty-three thousand, six hundred forty-four".