13691381 has 16 divisors (see below), whose sum is σ = 15892800. Its totient is φ = 11664000.

The previous prime is 13691351. The next prime is 13691387. The reversal of 13691381 is 18319631.

It is a cyclic number.

It is not a de Polignac number, because 13691381 - 2¹⁰ = 13690357 is a prime.

It is a super-2 number, since 2×13691381² = 374907827374322, which contains 22 as substring.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (13691387) 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, 22481 + ... + 23081.

It is an arithmetic number, because the mean of its divisors is an integer number (993300).

Almost surely, 2^13691381 is an apocalyptic number.

13691381 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

It is an amenable number.

13691381 is a deficient number, since it is larger than the sum of its proper divisors (2201419).

13691381 is a wasteful number, since it uses less digits than its factorization.

13691381 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 740.

The product of its digits is 3888, while the sum is 32.

The square root of 13691381 is about 3700.1866169154. The cubic root of 13691381 is about 239.2300615548.

The spelling of 13691381 in words is "thirteen million, six hundred ninety-one thousand, three hundred eighty-one".