13718021 has 4 divisors (see below), whose sum is σ = 13742700. Its totient is φ = 13693344.

The previous prime is 13718017. The next prime is 13718039. The reversal of 13718021 is 12081731.

It is a happy number.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 5244100 + 8473921 = 2290^2 + 2911^2 .

It is a cyclic number.

It is not a de Polignac number, because 13718021 - 2² = 13718017 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (13718071) 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, 11486 + ... + 12623.

It is an arithmetic number, because the mean of its divisors is an integer number (3435675).

Almost surely, 2^13718021 is an apocalyptic number.

It is an amenable number.

13718021 is a deficient number, since it is larger than the sum of its proper divisors (24679).

13718021 is an equidigital number, since it uses as much as digits as its factorization.

13718021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 24678.

The product of its (nonzero) digits is 336, while the sum is 23.

The square root of 13718021 is about 3703.7846859665. The cubic root of 13718021 is about 239.3851216330.

Adding to 13718021 its reverse (12081731), we get a palindrome (25799752).

The spelling of 13718021 in words is "thirteen million, seven hundred eighteen thousand, twenty-one".