3660388021 has 4 divisors (see below), whose sum is σ = 3720394444. Its totient is φ = 3600381600.

The previous prime is 3660387989. The next prime is 3660388027. The reversal of 3660388021 is 1208830663.

3660388021 is digitally balanced in base 3, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 145202500 + 3515185521 = 12050^2 + 59289^2 .

It is a cyclic number.

It is not a de Polignac number, because 3660388021 - 2⁵ = 3660387989 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (3660388027) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 30003120 + ... + 30003241.

It is an arithmetic number, because the mean of its divisors is an integer number (930098611).

Almost surely, 2^3660388021 is an apocalyptic number.

It is an amenable number.

3660388021 is a deficient number, since it is larger than the sum of its proper divisors (60006423).

3660388021 is an equidigital number, since it uses as much as digits as its factorization.

3660388021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 60006422.

The product of its (nonzero) digits is 41472, while the sum is 37.

The square root of 3660388021 is about 60501.1406586686. The cubic root of 3660388021 is about 1541.1410025296.

The spelling of 3660388021 in words is "three billion, six hundred sixty million, three hundred eighty-eight thousand, twenty-one".