400331280 has 80 divisors (see below), whose sum is σ = 1246527360. Its totient is φ = 106281984.

The previous prime is 400331279. The next prime is 400331357. The reversal of 400331280 is 82133004.

It is a happy number.

It is a tau number, because it is divible by the number of its divisors (80).

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 52341 + ... + 59499.

It is an arithmetic number, because the mean of its divisors is an integer number (15581592).

Almost surely, 2^400331280 is an apocalyptic number.

400331280 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 400331280, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (623263680).

400331280 is an abundant number, since it is smaller than the sum of its proper divisors (846196080).

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

400331280 is a wasteful number, since it uses less digits than its factorization.

400331280 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7408 (or 7402 counting only the distinct ones).

The product of its (nonzero) digits is 576, while the sum is 21.

The square root of 400331280 is about 20008.2802859216. The cubic root of 400331280 is about 737.0096512590.

Adding to 400331280 its reverse (82133004), we get a palindrome (482464284).

The spelling of 400331280 in words is "four hundred million, three hundred thirty-one thousand, two hundred eighty".