3991493 has 4 divisors (see below), whose sum is σ = 4354368. Its totient is φ = 3628620.

The previous prime is 3991469. The next prime is 3991511. The reversal of 3991493 is 3941993.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 3991493 - 2⁸ = 3991237 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (3991093) 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, 181421 + ... + 181442.

It is an arithmetic number, because the mean of its divisors is an integer number (1088592).

Almost surely, 2^3991493 is an apocalyptic number.

It is an amenable number.

3991493 is a deficient number, since it is larger than the sum of its proper divisors (362875).

3991493 is a wasteful number, since it uses less digits than its factorization.

3991493 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 362874.

The product of its digits is 26244, while the sum is 38.

The square root of 3991493 is about 1997.8721180296. The cubic root of 3991493 is about 158.6274918193.

The spelling of 3991493 in words is "three million, nine hundred ninety-one thousand, four hundred ninety-three".