3653721 has 16 divisors (see below), whose sum is σ = 5459520. Its totient is φ = 2414880.

The previous prime is 3653701. The next prime is 3653737. The reversal of 3653721 is 1273563.

It is a happy number.

3653721 is a `hidden beast` number, since 3 + 653 + 7 + 2 + 1 = 666.

3653721 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is not a de Polignac number, because 3653721 - 2¹⁰ = 3652697 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is not an unprimeable number, because it can be changed into a prime (3653701) 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 in 15 ways as a sum of consecutive naturals, for example, 3021 + ... + 4053.

It is an arithmetic number, because the mean of its divisors is an integer number (341220).

Almost surely, 2^3653721 is an apocalyptic number.

It is an amenable number.

3653721 is a deficient number, since it is larger than the sum of its proper divisors (1805799).

3653721 is a wasteful number, since it uses less digits than its factorization.

3653721 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1173 (or 1167 counting only the distinct ones).

The product of its digits is 3780, while the sum is 27.

The square root of 3653721 is about 1911.4708995954. The cubic root of 3653721 is about 154.0204757168.

The spelling of 3653721 in words is "three million, six hundred fifty-three thousand, seven hundred twenty-one".