3653843721 has 32 divisors (see below), whose sum is σ = 5501534208. Its totient is φ = 2137544640.

The previous prime is 3653843707. The next prime is 3653843729. The reversal of 3653843721 is 1273483563.

3653843721 is digitally balanced in base 2 and base 4, because in such bases it contains all the possibile digits an equal number of times.

It is not a de Polignac number, because 3653843721 - 2⁵ = 3653843689 is a prime.

It is a super-2 number, since 2×3653843721² = 26701147874982251682, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (3653843729) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 143286 + ... + 166848.

It is an arithmetic number, because the mean of its divisors is an integer number (171922944).

Almost surely, 2^3653843721 is an apocalyptic number.

It is an amenable number.

3653843721 is a deficient number, since it is larger than the sum of its proper divisors (1847690487).

3653843721 is a wasteful number, since it uses less digits than its factorization.

3653843721 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 23741.

The product of its digits is 362880, while the sum is 42.

The square root of 3653843721 is about 60447.0323589173. The cubic root of 3653843721 is about 1540.2220010815. Note that the first 3 decimals are identical.

The spelling of 3653843721 in words is "three billion, six hundred fifty-three million, eight hundred forty-three thousand, seven hundred twenty-one".