3728019821 has 2 divisors, whose sum is σ = 3728019822. Its totient is φ = 3728019820.

The previous prime is 3728019769. The next prime is 3728019847. The reversal of 3728019821 is 1289108273.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 3231354025 + 496665796 = 56845^2 + 22286^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-3728019821 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (3728019851) 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, 1864009910 + 1864009911.

It is an arithmetic number, because the mean of its divisors is an integer number (1864009911).

Almost surely, 2^3728019821 is an apocalyptic number.

It is an amenable number.

3728019821 is a deficient number, since it is larger than the sum of its proper divisors (1).

3728019821 is an equidigital number, since it uses as much as digits as its factorization.

3728019821 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 48384, while the sum is 41.

The square root of 3728019821 is about 61057.5124042898. The cubic root of 3728019821 is about 1550.5748573245.

The spelling of 3728019821 in words is "three billion, seven hundred twenty-eight million, nineteen thousand, eight hundred twenty-one".