3919909621 has 4 divisors (see below), whose sum is σ = 3932514144. Its totient is φ = 3907305100.

The previous prime is 3919909603. The next prime is 3919909661. The reversal of 3919909621 is 1269099193.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 1269099193 = 67 ⋅18941779.

It is a cyclic number.

It is not a de Polignac number, because 3919909621 - 2⁹ = 3919909109 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 (3919909661) 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, 6301795 + ... + 6302416.

It is an arithmetic number, because the mean of its divisors is an integer number (983128536).

Almost surely, 2^3919909621 is an apocalyptic number.

It is an amenable number.

3919909621 is a deficient number, since it is larger than the sum of its proper divisors (12604523).

3919909621 is a wasteful number, since it uses less digits than its factorization.

3919909621 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 12604522.

The product of its (nonzero) digits is 236196, while the sum is 49.

The square root of 3919909621 is about 62609.1816030205. The cubic root of 3919909621 is about 1576.7349147711.

The spelling of 3919909621 in words is "three billion, nine hundred nineteen million, nine hundred nine thousand, six hundred twenty-one".