3944164021 has 4 divisors (see below), whose sum is σ = 4507616032. Its totient is φ = 3380712012.

The previous prime is 3944164013. The next prime is 3944164027. The reversal of 3944164021 is 1204614493.

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 3944164021 - 2³ = 3944164013 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 (3944164027) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 281725995 + ... + 281726008.

It is an arithmetic number, because the mean of its divisors is an integer number (1126904008).

Almost surely, 2^3944164021 is an apocalyptic number.

It is an amenable number.

3944164021 is a deficient number, since it is larger than the sum of its proper divisors (563452011).

3944164021 is an equidigital number, since it uses as much as digits as its factorization.

3944164021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 563452010.

The product of its (nonzero) digits is 20736, while the sum is 34.

The square root of 3944164021 is about 62802.5797320460. The cubic root of 3944164021 is about 1579.9802407666.

The spelling of 3944164021 in words is "three billion, nine hundred forty-four million, one hundred sixty-four thousand, twenty-one".