13781245 has 4 divisors (see below), whose sum is σ = 16537500. Its totient is φ = 11024992.

The previous prime is 13781239. The next prime is 13781263. The reversal of 13781245 is 54218731.

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 7601049 + 6180196 = 2757^2 + 2486^2 .

It is a cyclic number.

It is not a de Polignac number, because 13781245 - 2⁹ = 13780733 is a prime.

It is a congruent number.

It is an unprimeable number.

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 3 ways as a sum of consecutive naturals, for example, 1378120 + ... + 1378129.

It is an arithmetic number, because the mean of its divisors is an integer number (4134375).

Almost surely, 2^13781245 is an apocalyptic number.

It is an amenable number.

13781245 is a deficient number, since it is larger than the sum of its proper divisors (2756255).

13781245 is an equidigital number, since it uses as much as digits as its factorization.

13781245 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2756254.

The product of its digits is 6720, while the sum is 31.

The square root of 13781245 is about 3712.3099277943. The cubic root of 13781245 is about 239.7523197131.

Adding to 13781245 its reverse (54218731), we get a palindrome (67999976).

The spelling of 13781245 in words is "thirteen million, seven hundred eighty-one thousand, two hundred forty-five".