3821991 has 8 divisors (see below), whose sum is σ = 5395824. Its totient is φ = 2398080.

The previous prime is 3821981. The next prime is 3822017. The reversal of 3821991 is 1991283.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 3821991 - 2⁷ = 3821863 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (3821911) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 37420 + ... + 37521.

It is an arithmetic number, because the mean of its divisors is an integer number (674478).

Almost surely, 2^3821991 is an apocalyptic number.

3821991 is a deficient number, since it is larger than the sum of its proper divisors (1573833).

3821991 is a wasteful number, since it uses less digits than its factorization.

3821991 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 74961.

The product of its digits is 3888, while the sum is 33.

The square root of 3821991 is about 1954.9913043285. The cubic root of 3821991 is about 156.3495203856.

The spelling of 3821991 in words is "three million, eight hundred twenty-one thousand, nine hundred ninety-one".