13693981 has 12 divisors (see below), whose sum is σ = 16233372. Its totient is φ = 11514048.

The previous prime is 13693969. The next prime is 13693987. The reversal of 13693981 is 18939631.

13693981 is digitally balanced in base 2 and base 8, because in such bases it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in 2 ways, for example, as 8357881 + 5336100 = 2891^2 + 2310^2 .

It is not a de Polignac number, because 13693981 - 2⁷ = 13693853 is a prime.

It is a super-2 number, since 2×13693981² = 375050231256722, which contains 22 as substring.

It is a Duffinian number.

13693981 is strictly pandigital in base 8.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (13693987) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 40 + ... + 5233.

It is an arithmetic number, because the mean of its divisors is an integer number (1352781).

Almost surely, 2^13693981 is an apocalyptic number.

It is an amenable number.

13693981 is a deficient number, since it is larger than the sum of its proper divisors (2539391).

13693981 is an equidigital number, since it uses as much as digits as its factorization.

13693981 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5340 (or 5333 counting only the distinct ones).

The product of its digits is 34992, while the sum is 40.

The square root of 13693981 is about 3700.5379338685. The cubic root of 13693981 is about 239.2452038985.

The spelling of 13693981 in words is "thirteen million, six hundred ninety-three thousand, nine hundred eighty-one".