13781147 has 4 divisors (see below), whose sum is σ = 13917696. Its totient is φ = 13644600.

The previous prime is 13781129. The next prime is 13781149. The reversal of 13781147 is 74118731.

It is a happy number.

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-13781147 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (13781149) 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, 68123 + ... + 68324.

It is an arithmetic number, because the mean of its divisors is an integer number (3479424).

Almost surely, 2^13781147 is an apocalyptic number.

13781147 is a deficient number, since it is larger than the sum of its proper divisors (136549).

13781147 is a wasteful number, since it uses less digits than its factorization.

13781147 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 136548.

The product of its digits is 4704, while the sum is 32.

The square root of 13781147 is about 3712.2967284418. The cubic root of 13781147 is about 239.7517514097.

Adding to 13781147 its reverse (74118731), we get a palindrome (87899878).

The spelling of 13781147 in words is "thirteen million, seven hundred eighty-one thousand, one hundred forty-seven".