400543920 has 320 divisors, whose sum is σ = 1607040000. Its totient is φ = 89800704.

The previous prime is 400543879. The next prime is 400543931. The reversal of 400543920 is 29345004.

It is a Harshad number since it is a multiple of its sum of digits (27).

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 63 ways as a sum of consecutive naturals, for example, 891856 + ... + 892304.

It is an arithmetic number, because the mean of its divisors is an integer number (5022000).

Almost surely, 2^400543920 is an apocalyptic number.

400543920 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 400543920, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (803520000).

400543920 is an abundant number, since it is smaller than the sum of its proper divisors (1206496080).

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

400543920 is a wasteful number, since it uses less digits than its factorization.

400543920 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 537 (or 525 counting only the distinct ones).

The product of its (nonzero) digits is 4320, while the sum is 27.

The square root of 400543920 is about 20013.5933805002. The cubic root of 400543920 is about 737.1401182004.

Adding to 400543920 its reverse (29345004), we get a palindrome (429888924).

The spelling of 400543920 in words is "four hundred million, five hundred forty-three thousand, nine hundred twenty".