3920991 has 4 divisors (see below), whose sum is σ = 5227992. Its totient is φ = 2613992.

The previous prime is 3920989. The next prime is 3921023. The reversal of 3920991 is 1990293.

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 3920991 - 2¹ = 3920989 is a prime.

It is a D-number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (3920941) 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, 653496 + ... + 653501.

It is an arithmetic number, because the mean of its divisors is an integer number (1306998).

Almost surely, 2^3920991 is an apocalyptic number.

3920991 is a deficient number, since it is larger than the sum of its proper divisors (1307001).

3920991 is a wasteful number, since it uses less digits than its factorization.

3920991 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1307000.

The product of its (nonzero) digits is 4374, while the sum is 33.

The square root of 3920991 is about 1980.1492368001. The cubic root of 3920991 is about 157.6879891860.

The spelling of 3920991 in words is "three million, nine hundred twenty thousand, nine hundred ninety-one".