400043440 has 20 divisors (see below), whose sum is σ = 930101184. Its totient is φ = 160017344.

The previous prime is 400043401. The next prime is 400043443. The reversal of 400043440 is 44340004.

It is a tau number, because it is divible by the number of its divisors (20).

It is a super-4 number, since 4×400043440⁴ (a number of 36 digits) contains 4444 as substring.

It is not an unprimeable number, because it can be changed into a prime (400043443) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2500192 + ... + 2500351.

Almost surely, 2^400043440 is an apocalyptic number.

400043440 is a gapful number since it is divisible by the number (40) formed by its first and last digit.

It is an amenable number.

400043440 is an abundant number, since it is smaller than the sum of its proper divisors (530057744).

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

400043440 is a wasteful number, since it uses less digits than its factorization.

400043440 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5000556 (or 5000550 counting only the distinct ones).

The product of its (nonzero) digits is 768, while the sum is 19.

The square root of 400043440 is about 20001.0859705167. The cubic root of 400043440 is about 736.8329711506.

Adding to 400043440 its reverse (44340004), we get a palindrome (444383444).

The spelling of 400043440 in words is "four hundred million, forty-three thousand, four hundred forty".