400400440 has 64 divisors (see below), whose sum is σ = 995328000. Its totient is φ = 143744640.

The previous prime is 400400437. The next prime is 400400443. The reversal of 400400440 is 44004004.

400400440 = 4995² + 4996² + ... + 5010².

It is an interprime number because it is at equal distance from previous prime (400400437) and next prime (400400443).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (400400443) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 29001 + ... + 40519.

It is an arithmetic number, because the mean of its divisors is an integer number (15552000).

Almost surely, 2^400400440 is an apocalyptic number.

400400440 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 400400440, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (497664000).

400400440 is an abundant number, since it is smaller than the sum of its proper divisors (594927560).

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

400400440 is a wasteful number, since it uses less digits than its factorization.

400400440 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 11620 (or 11616 counting only the distinct ones).

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

The square root of 400400440 is about 20010.0084957503. The cubic root of 400400440 is about 737.0520899883.

Adding to 400400440 its reverse (44004004), we get a palindrome (444404444).

The spelling of 400400440 in words is "four hundred million, four hundred thousand, four hundred forty".