13681919 has 4 divisors (see below), whose sum is σ = 14402040. Its totient is φ = 12961800.

The previous prime is 13681907. The next prime is 13681951. The reversal of 13681919 is 91918631.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 91918631 = 7 ⋅13131233.

It is not a de Polignac number, because 13681919 - 2⁸ = 13681663 is a prime.

It is a super-2 number, since 2×13681919² = 374389815045122, which contains 22 as substring.

It is a Duffinian number.

13681919 is a modest number, since divided by 1919 gives 1368 as remainder.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (13681979) 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, 360032 + ... + 360069.

It is an arithmetic number, because the mean of its divisors is an integer number (3600510).

Almost surely, 2^13681919 is an apocalyptic number.

13681919 is a gapful number since it is divisible by the number (19) formed by its first and last digit.

13681919 is a deficient number, since it is larger than the sum of its proper divisors (720121).

13681919 is an equidigital number, since it uses as much as digits as its factorization.

13681919 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 720120.

The product of its digits is 11664, while the sum is 38.

The square root of 13681919 is about 3698.9078117736. The cubic root of 13681919 is about 239.1749388833.

The spelling of 13681919 in words is "thirteen million, six hundred eighty-one thousand, nine hundred nineteen".