3639363721 has 12 divisors (see below), whose sum is σ = 4456364880. Its totient is φ = 2955272040.

The previous prime is 3639363713. The next prime is 3639363731. The reversal of 3639363721 is 1273639363.

It is not a de Polignac number, because 3639363721 - 2³ = 3639363713 is a prime.

It is not an unprimeable number, because it can be changed into a prime (3639363731) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 1953615 + ... + 1955476.

It is an arithmetic number, because the mean of its divisors is an integer number (371363740).

Almost surely, 2^3639363721 is an apocalyptic number.

It is an amenable number.

3639363721 is a deficient number, since it is larger than the sum of its proper divisors (817001159).

3639363721 is a wasteful number, since it uses less digits than its factorization.

3639363721 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3909124 (or 3909117 counting only the distinct ones).

The product of its digits is 367416, while the sum is 43.

The square root of 3639363721 is about 60327.1391746700. The cubic root of 3639363721 is about 1538.1846998691.

The spelling of 3639363721 in words is "three billion, six hundred thirty-nine million, three hundred sixty-three thousand, seven hundred twenty-one".