3821891 has 4 divisors (see below), whose sum is σ = 3830712. Its totient is φ = 3813072.

The previous prime is 3821863. The next prime is 3821893. The reversal of 3821891 is 1981283.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 1981283 = 283 ⋅7001.

It is a cyclic number.

It is not a de Polignac number, because 3821891 - 2⁶ = 3821827 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (3821893) 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, 3725 + ... + 4638.

It is an arithmetic number, because the mean of its divisors is an integer number (957678).

Almost surely, 2^3821891 is an apocalyptic number.

3821891 is a deficient number, since it is larger than the sum of its proper divisors (8821).

3821891 is an equidigital number, since it uses as much as digits as its factorization.

3821891 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8820.

The product of its digits is 3456, while the sum is 32.

The square root of 3821891 is about 1954.9657285999. The cubic root of 3821891 is about 156.3481567780.

The spelling of 3821891 in words is "three million, eight hundred twenty-one thousand, eight hundred ninety-one".