13721238 has 32 divisors (see below), whose sum is σ = 30877920. Its totient is φ = 4572288.

The previous prime is 13721237. The next prime is 13721243. The reversal of 13721238 is 83212731.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (13721231) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 2806 + ... + 5942.

It is an arithmetic number, because the mean of its divisors is an integer number (964935).

Almost surely, 2^13721238 is an apocalyptic number.

13721238 is a gapful number since it is divisible by the number (18) formed by its first and last digit.

It is a practical number, because each smaller number is the sum of distinct divisors of 13721238, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (15438960).

13721238 is an abundant number, since it is smaller than the sum of its proper divisors (17156682).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

13721238 is an frugal number, since it uses more digits than its factorization.

13721238 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3160 (or 3142 counting only the distinct ones).

The product of its digits is 2016, while the sum is 27.

The square root of 13721238 is about 3704.2189460128. The cubic root of 13721238 is about 239.4038328291.

Adding to 13721238 its reverse (83212731), we get a palindrome (96933969).

The spelling of 13721238 in words is "thirteen million, seven hundred twenty-one thousand, two hundred thirty-eight".