3913819821 has 12 divisors (see below), whose sum is σ = 5759961948. Its totient is φ = 2559982464.

The previous prime is 3913819801. The next prime is 3913819829. The reversal of 3913819821 is 1289183193.

3913819821 is digitally balanced in base 3, because in such base it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in 2 ways, for example, as 2354675625 + 1559144196 = 48525^2 + 39486^2 .

It is not a de Polignac number, because 3913819821 - 2¹⁴ = 3913803437 is a prime.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (3913819829) 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, 4102060 + ... + 4103013.

It is an arithmetic number, because the mean of its divisors is an integer number (479996829).

Almost surely, 2^3913819821 is an apocalyptic number.

It is an amenable number.

3913819821 is a deficient number, since it is larger than the sum of its proper divisors (1846142127).

3913819821 is a wasteful number, since it uses less digits than its factorization.

3913819821 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8205132 (or 8205129 counting only the distinct ones).

The product of its digits is 93312, while the sum is 45.

The square root of 3913819821 is about 62560.5292576717. The cubic root of 3913819821 is about 1575.9179761233.

The spelling of 3913819821 in words is "three billion, nine hundred thirteen million, eight hundred nineteen thousand, eight hundred twenty-one".