400440400 has 60 divisors (see below), whose sum is σ = 963982944. Its totient is φ = 159856000.

The previous prime is 400440379. The next prime is 400440401. The reversal of 400440400 is 4044004.

It is a Harshad number since it is a multiple of its sum of digits (16).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (400440401) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 387885 + ... + 388915.

Almost surely, 2^400440400 is an apocalyptic number.

400440400 is a gapful number since it is divisible by the number (40) formed by its first and last digit.

It is an amenable number.

400440400 is an abundant number, since it is smaller than the sum of its proper divisors (563542544).

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

400440400 is a wasteful number, since it uses less digits than its factorization.

400440400 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2020 (or 2009 counting only the distinct ones).

The product of its (nonzero) digits is 256, while the sum is 16.

The square root of 400440400 is about 20011.0069711646. The cubic root of 400440400 is about 737.0766084610.

Adding to 400440400 its reverse (4044004), we get a palindrome (404484404).

The spelling of 400440400 in words is "four hundred million, four hundred forty thousand, four hundred".