3923921 has 4 divisors (see below), whose sum is σ = 3968100. Its totient is φ = 3879744.

The previous prime is 3923917. The next prime is 3923963. The reversal of 3923921 is 1293293.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 1293293 = 193 ⋅6701.

It can be written as a sum of positive squares in 2 ways, for example, as 1234321 + 2689600 = 1111^2 + 1640^2 .

It is a cyclic number.

It is not a de Polignac number, because 3923921 - 2² = 3923917 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (3923911) 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, 21956 + ... + 22133.

It is an arithmetic number, because the mean of its divisors is an integer number (992025).

Almost surely, 2^3923921 is an apocalyptic number.

It is an amenable number.

3923921 is a deficient number, since it is larger than the sum of its proper divisors (44179).

3923921 is an equidigital number, since it uses as much as digits as its factorization.

3923921 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 44178.

The product of its digits is 2916, while the sum is 29.

The square root of 3923921 is about 1980.8889418642. Note that the first 3 decimals coincide. The cubic root of 3923921 is about 157.7272573856.

The spelling of 3923921 in words is "three million, nine hundred twenty-three thousand, nine hundred twenty-one".