3684559721 has 2 divisors, whose sum is σ = 3684559722. Its totient is φ = 3684559720.

The previous prime is 3684559717. The next prime is 3684559729. The reversal of 3684559721 is 1279554863.

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., 3250254121 + 434305600 = 57011^2 + 20840^2 .

It is a cyclic number.

It is not a de Polignac number, because 3684559721 - 2² = 3684559717 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 3684559721.

It is not a weakly prime, because it can be changed into another prime (3684559729) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1842279860 + 1842279861.

It is an arithmetic number, because the mean of its divisors is an integer number (1842279861).

Almost surely, 2^3684559721 is an apocalyptic number.

It is an amenable number.

3684559721 is a deficient number, since it is larger than the sum of its proper divisors (1).

3684559721 is an equidigital number, since it uses as much as digits as its factorization.

3684559721 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 1814400, while the sum is 50.

The square root of 3684559721 is about 60700.5743053556. The cubic root of 3684559721 is about 1544.5259167608.

The spelling of 3684559721 in words is "three billion, six hundred eighty-four million, five hundred fifty-nine thousand, seven hundred twenty-one".