13729981 has 4 divisors (see below), whose sum is σ = 13795264. Its totient is φ = 13664700.

The previous prime is 13729973. The next prime is 13730023. The reversal of 13729981 is 18992731.

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 13729981 - 2³ = 13729973 is a prime.

It is a super-2 number, since 2×13729981² = 377024756520722, 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 (13729901) 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, 32325 + ... + 32746.

It is an arithmetic number, because the mean of its divisors is an integer number (3448816).

Almost surely, 2^13729981 is an apocalyptic number.

13729981 is the 2344-th centered pentagonal number.

It is an amenable number.

13729981 is a deficient number, since it is larger than the sum of its proper divisors (65283).

13729981 is an equidigital number, since it uses as much as digits as its factorization.

13729981 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 65282.

The product of its digits is 27216, while the sum is 40.

The square root of 13729981 is about 3705.3988989041. The cubic root of 13729981 is about 239.4546704018.

The spelling of 13729981 in words is "thirteen million, seven hundred twenty-nine thousand, nine hundred eighty-one".