6691381 has 4 divisors (see below), whose sum is σ = 6907264. Its totient is φ = 6475500.

The previous prime is 6691369. The next prime is 6691397. The reversal of 6691381 is 1831966.

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 6691381 - 2²¹ = 4594229 is a prime.

It is a super-2 number, since 2×6691381² = 89549159374322, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (6691301) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 107895 + ... + 107956.

It is an arithmetic number, because the mean of its divisors is an integer number (1726816).

Almost surely, 2^6691381 is an apocalyptic number.

It is an amenable number.

6691381 is a deficient number, since it is larger than the sum of its proper divisors (215883).

6691381 is a wasteful number, since it uses less digits than its factorization.

6691381 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 215882.

The product of its digits is 7776, while the sum is 34.

The square root of 6691381 is about 2586.7703802232. The cubic root of 6691381 is about 188.4394897560.

The spelling of 6691381 in words is "six million, six hundred ninety-one thousand, three hundred eighty-one".