13117840 has 20 divisors (see below), whose sum is σ = 30499164. Its totient is φ = 5247104.

The previous prime is 13117837. The next prime is 13117849. The reversal of 13117840 is 4871131.

It can be written as a sum of positive squares in 2 ways, for example, as 3283344 + 9834496 = 1812^2 + 3136^2 .

It is a tau number, because it is divible by the number of its divisors (20).

It is not an unprimeable number, because it can be changed into a prime (13117849) 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, 81907 + ... + 82066.

Almost surely, 2^13117840 is an apocalyptic number.

13117840 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

13117840 is an abundant number, since it is smaller than the sum of its proper divisors (17381324).

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

13117840 is a wasteful number, since it uses less digits than its factorization.

13117840 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 163986 (or 163980 counting only the distinct ones).

The product of its (nonzero) digits is 672, while the sum is 25.

The square root of 13117840 is about 3621.8558778615. The cubic root of 13117840 is about 235.8417976404.

Adding to 13117840 its reverse (4871131), we get a palindrome (17988971).

It can be divided in two parts, 131 and 17840, that added together give a palindrome (17971).

The spelling of 13117840 in words is "thirteen million, one hundred seventeen thousand, eight hundred forty".