3691993 has 4 divisors (see below), whose sum is σ = 3713508. Its totient is φ = 3670480.

The previous prime is 3691957. The next prime is 3692021. The reversal of 3691993 is 3991963.

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

It can be written as a sum of positive squares in 2 ways, for example, as 3564544 + 127449 = 1888^2 + 357^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-3691993 is a prime.

It is a Duffinian number.

3691993 is a lucky number.

It is not an unprimeable number, because it can be changed into a prime (3691913) 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, 10498 + ... + 10843.

It is an arithmetic number, because the mean of its divisors is an integer number (928377).

Almost surely, 2^3691993 is an apocalyptic number.

It is an amenable number.

3691993 is a deficient number, since it is larger than the sum of its proper divisors (21515).

3691993 is a wasteful number, since it uses less digits than its factorization.

3691993 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 21514.

The product of its digits is 39366, while the sum is 40.

The square root of 3691993 is about 1921.4559583816. The cubic root of 3691993 is about 154.5563868014.

It can be divided in two parts, 36 and 91993, that added together give a palindrome (92029).

The spelling of 3691993 in words is "three million, six hundred ninety-one thousand, nine hundred ninety-three".