400043020 has 24 divisors (see below), whose sum is σ = 904713264. Its totient is φ = 147708096.

The previous prime is 400043011. The next prime is 400043051. The reversal of 400043020 is 20340004.

It is a Harshad number since it is a multiple of its sum of digits (13).

400043020 is a modest number, since divided by 43020 gives 40 as remainder.

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 7 ways as a sum of consecutive naturals, for example, 769054 + ... + 769573.

It is an arithmetic number, because the mean of its divisors is an integer number (37696386).

Almost surely, 2^400043020 is an apocalyptic number.

It is an amenable number.

400043020 is an abundant number, since it is smaller than the sum of its proper divisors (504670244).

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

400043020 is a wasteful number, since it uses less digits than its factorization.

400043020 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1538649 (or 1538647 counting only the distinct ones).

The product of its (nonzero) digits is 96, while the sum is 13.

The square root of 400043020 is about 20001.0754710840. The cubic root of 400043020 is about 736.8327132870.

Adding to 400043020 its reverse (20340004), we get a palindrome (420383024).

The spelling of 400043020 in words is "four hundred million, forty-three thousand, twenty".