3920621921 has 4 divisors (see below), whose sum is σ = 3987073200. Its totient is φ = 3854170644.

The previous prime is 3920621909. The next prime is 3920621927. The reversal of 3920621921 is 1291260293.

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.

It is a cyclic number.

It is not a de Polignac number, because 3920621921 - 2¹⁰ = 3920620897 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (3920621927) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 33225551 + ... + 33225668.

It is an arithmetic number, because the mean of its divisors is an integer number (996768300).

Almost surely, 2^3920621921 is an apocalyptic number.

It is an amenable number.

3920621921 is a deficient number, since it is larger than the sum of its proper divisors (66451279).

3920621921 is an equidigital number, since it uses as much as digits as its factorization.

3920621921 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 66451278.

The product of its (nonzero) digits is 11664, while the sum is 35.

The square root of 3920621921 is about 62614.8698074187. The cubic root of 3920621921 is about 1576.8304135936.

The spelling of 3920621921 in words is "three billion, nine hundred twenty million, six hundred twenty-one thousand, nine hundred twenty-one".