400340321 has 4 divisors (see below), whose sum is σ = 405408000. Its totient is φ = 395272644.

The previous prime is 400340261. The next prime is 400340329. The reversal of 400340321 is 123043004.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-400340321 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 400340321.

It is not an unprimeable number, because it can be changed into a prime (400340329) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2533721 + ... + 2533878.

It is an arithmetic number, because the mean of its divisors is an integer number (101352000).

Almost surely, 2^400340321 is an apocalyptic number.

It is an amenable number.

400340321 is a deficient number, since it is larger than the sum of its proper divisors (5067679).

400340321 is an equidigital number, since it uses as much as digits as its factorization.

400340321 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5067678.

The product of its (nonzero) digits is 288, while the sum is 17.

The square root of 400340321 is about 20008.5062161072. The cubic root of 400340321 is about 737.0151993758.

Adding to 400340321 its reverse (123043004), we get a palindrome (523383325).

The spelling of 400340321 in words is "four hundred million, three hundred forty thousand, three hundred twenty-one".