3644021789 has 2 divisors, whose sum is σ = 3644021790. Its totient is φ = 3644021788.

The previous prime is 3644021783. The next prime is 3644021807. The reversal of 3644021789 is 9871204463.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 2781718564 + 862303225 = 52742^2 + 29365^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-3644021789 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (3644021783) 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 as a sum of consecutive naturals, namely, 1822010894 + 1822010895.

It is an arithmetic number, because the mean of its divisors is an integer number (1822010895).

Almost surely, 2^3644021789 is an apocalyptic number.

It is an amenable number.

3644021789 is a deficient number, since it is larger than the sum of its proper divisors (1).

3644021789 is an equidigital number, since it uses as much as digits as its factorization.

3644021789 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 290304, while the sum is 44.

The square root of 3644021789 is about 60365.7335663206. The cubic root of 3644021789 is about 1538.8406674873.

The spelling of 3644021789 in words is "three billion, six hundred forty-four million, twenty-one thousand, seven hundred eighty-nine".