400400404000 has 96 divisors (see below), whose sum is σ = 984909128112. Its totient is φ = 159976960000.

The previous prime is 400400403973. The next prime is 400400404013. The reversal of 400400404000 is 404004004.

It can be written as a sum of positive squares in 8 ways, for example, as 16 + 400400403984 = 4^2 + 632772^2 .

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

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 3467190 + ... + 3580810.

Almost surely, 2^400400404000 is an apocalyptic number.

400400404000 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 400400404000, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (492454564056).

400400404000 is an abundant number, since it is smaller than the sum of its proper divisors (584508724112).

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

400400404000 is a wasteful number, since it uses less digits than its factorization.

400400404000 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 114527 (or 114509 counting only the distinct ones).

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

Subtracting from 400400404000 its sum of digits (16), we obtain a square (400400403984 = 632772²).

Adding to 400400404000 its reverse (404004004), we get a palindrome (400804408004).

The spelling of 400400404000 in words is "four hundred billion, four hundred million, four hundred four thousand".