3653409721 has 6 divisors (see below), whose sum is σ = 3956059230. Its totient is φ = 3372378048.

The previous prime is 3653409709. The next prime is 3653409797. The reversal of 3653409721 is 1279043563.

It is a happy number.

It can be written as a sum of positive squares in 3 ways, for example, as 385572496 + 3267837225 = 19636^2 + 57165^2 .

It is not a de Polignac number, because 3653409721 - 2¹¹ = 3653407673 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (3653409121) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 10808736 + ... + 10809073.

It is an arithmetic number, because the mean of its divisors is an integer number (659343205).

Almost surely, 2^3653409721 is an apocalyptic number.

It is an amenable number.

3653409721 is a deficient number, since it is larger than the sum of its proper divisors (302649509).

3653409721 is a wasteful number, since it uses less digits than its factorization.

3653409721 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 21617835 (or 21617822 counting only the distinct ones).

The product of its (nonzero) digits is 136080, while the sum is 40.

The square root of 3653409721 is about 60443.4423324814. The cubic root of 3653409721 is about 1540.1610166436.

The spelling of 3653409721 in words is "three billion, six hundred fifty-three million, four hundred nine thousand, seven hundred twenty-one".