684004001 has 2 divisors, whose sum is σ = 684004002. Its totient is φ = 684004000.

The previous prime is 684003997. The next prime is 684004007. The reversal of 684004001 is 100400486.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 506475025 + 177528976 = 22505^2 + 13324^2 .

It is a cyclic number.

It is not a de Polignac number, because 684004001 - 2² = 684003997 is a prime.

It is a super-2 number, since 2×684004001² = 935722946768016002, which contains 22 as substring.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (684004007) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 342002000 + 342002001.

It is an arithmetic number, because the mean of its divisors is an integer number (342002001).

Almost surely, 2^684004001 is an apocalyptic number.

It is an amenable number.

684004001 is a deficient number, since it is larger than the sum of its proper divisors (1).

684004001 is an equidigital number, since it uses as much as digits as its factorization.

684004001 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 768, while the sum is 23.

The square root of 684004001 is about 26153.4701521615. The cubic root of 684004001 is about 881.0885294352.

Adding to 684004001 its reverse (100400486), we get a palindrome (784404487).

The spelling of 684004001 in words is "six hundred eighty-four million, four thousand, one".