13720138 has 4 divisors (see below), whose sum is σ = 20580210. Its totient is φ = 6860068.

The previous prime is 13720129. The next prime is 13720159. The reversal of 13720138 is 83102731.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 83102731 = 71 ⋅1170461.

It can be written as a sum of positive squares in only one way, i.e., 13520329 + 199809 = 3677^2 + 447^2 .

It is a zygodrome in base 7.

It is an unprimeable number.

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 as a sum of consecutive naturals, namely, 3430033 + ... + 3430036.

Almost surely, 2^13720138 is an apocalyptic number.

13720138 is a deficient number, since it is larger than the sum of its proper divisors (6860072).

13720138 is an equidigital number, since it uses as much as digits as its factorization.

13720138 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6860071.

The product of its (nonzero) digits is 1008, while the sum is 25.

The square root of 13720138 is about 3704.0704636926. The cubic root of 13720138 is about 239.3974351738.

Adding to 13720138 its reverse (83102731), we get a palindrome (96822869).

The spelling of 13720138 in words is "thirteen million, seven hundred twenty thousand, one hundred thirty-eight".