400403820 has 24 divisors (see below), whose sum is σ = 1121130864. Its totient is φ = 106774336.

The previous prime is 400403819. The next prime is 400403863. The reversal of 400403820 is 28304004.

It is a happy number.

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 7 ways as a sum of consecutive naturals, for example, 3336639 + ... + 3336758.

It is an arithmetic number, because the mean of its divisors is an integer number (46713786).

Almost surely, 2^400403820 is an apocalyptic number.

It is an amenable number.

400403820 is an abundant number, since it is smaller than the sum of its proper divisors (720727044).

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

400403820 is a wasteful number, since it uses less digits than its factorization.

400403820 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6673409 (or 6673407 counting only the distinct ones).

The product of its (nonzero) digits is 768, while the sum is 21.

The square root of 400403820 is about 20010.0929533073. The cubic root of 400403820 is about 737.0541639363.

Adding to 400403820 its reverse (28304004), we get a palindrome (428707824).

The spelling of 400403820 in words is "four hundred million, four hundred three thousand, eight hundred twenty".