3891993 has 16 divisors (see below), whose sum is σ = 6092160. Its totient is φ = 2163456.

The previous prime is 3891977. The next prime is 3892001. The reversal of 3891993 is 3991983.

It is a happy number.

It is not a de Polignac number, because 3891993 - 2⁴ = 3891977 is a prime.

It is a Curzon number.

3891993 is a lucky number.

It is not an unprimeable number, because it can be changed into a prime (3891913) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1728 + ... + 3281.

It is an arithmetic number, because the mean of its divisors is an integer number (380760).

Almost surely, 2^3891993 is an apocalyptic number.

It is an amenable number.

3891993 is a deficient number, since it is larger than the sum of its proper divisors (2200167).

3891993 is a wasteful number, since it uses less digits than its factorization.

3891993 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5056.

The product of its digits is 52488, while the sum is 42.

The square root of 3891993 is about 1972.8134731900. The cubic root of 3891993 is about 157.2982955868.

It can be divided in two parts, 3891 and 993, that added together give a palindrome (4884).

The spelling of 3891993 in words is "three million, eight hundred ninety-one thousand, nine hundred ninety-three".