3927721 has 4 divisors (see below), whose sum is σ = 4488832. Its totient is φ = 3366612.

The previous prime is 3927713. The next prime is 3927727. The reversal of 3927721 is 1277293.

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: 1277293 = 31 ⋅41203.

It is a cyclic number.

It is not a de Polignac number, because 3927721 - 2³ = 3927713 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (3927727) 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, 280545 + ... + 280558.

It is an arithmetic number, because the mean of its divisors is an integer number (1122208).

Almost surely, 2^3927721 is an apocalyptic number.

It is an amenable number.

3927721 is a deficient number, since it is larger than the sum of its proper divisors (561111).

3927721 is an equidigital number, since it uses as much as digits as its factorization.

3927721 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 561110.

The product of its digits is 5292, while the sum is 31.

The square root of 3927721 is about 1981.8478750903. The cubic root of 3927721 is about 157.7781563210.

The spelling of 3927721 in words is "three million, nine hundred twenty-seven thousand, seven hundred twenty-one".