3843991 has 4 divisors (see below), whose sum is σ = 3901432. Its totient is φ = 3786552.

The previous prime is 3843977. The next prime is 3844019. The reversal of 3843991 is 1993483.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 3843991 - 2¹⁹ = 3319703 is a prime.

It is a Duffinian number.

3843991 is a lucky number.

It is a self number, because there is not a number n which added to its sum of digits gives 3843991.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (3843941) 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, 28620 + ... + 28753.

It is an arithmetic number, because the mean of its divisors is an integer number (975358).

Almost surely, 2^3843991 is an apocalyptic number.

3843991 is a deficient number, since it is larger than the sum of its proper divisors (57441).

3843991 is an equidigital number, since it uses as much as digits as its factorization.

3843991 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 57440.

The product of its digits is 23328, while the sum is 37.

The square root of 3843991 is about 1960.6098541015. The cubic root of 3843991 is about 156.6489376850.

It can be divided in two parts, 384399 and 1, that added together give a square (384400 = 620²).

The spelling of 3843991 in words is "three million, eight hundred forty-three thousand, nine hundred ninety-one".