3909644221791 has 24 divisors (see below), whose sum is σ = 6548384816512. Its totient is φ = 2030984010000.

The previous prime is 3909644221757. The next prime is 3909644221829. The reversal of 3909644221791 is 1971224469093.

It is a happy number.

It is not a de Polignac number, because 3909644221791 - 2⁷ = 3909644221663 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (3909644221741) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 769309585 + ... + 769314666.

Almost surely, 2^{3909644221791} is an apocalyptic number.

3909644221791 is a deficient number, since it is larger than the sum of its proper divisors (2638740594721).

3909644221791 is a wasteful number, since it uses less digits than its factorization.

3909644221791 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1538624283 (or 1538624272 counting only the distinct ones).

The product of its (nonzero) digits is 5878656, while the sum is 57.

The spelling of 3909644221791 in words is "three trillion, nine hundred nine billion, six hundred forty-four million, two hundred twenty-one thousand, seven hundred ninety-one".