13111640 has 32 divisors (see below), whose sum is σ = 29680560. Its totient is φ = 5212800.

The previous prime is 13111639. The next prime is 13111643. The reversal of 13111640 is 4611131.

It is a Cunningham number, because it is equal to 3621²-1.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (13111643) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 6335 + ... + 8145.

Almost surely, 2^13111640 is an apocalyptic number.

13111640 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

13111640 is an abundant number, since it is smaller than the sum of its proper divisors (16568920).

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

13111640 is a wasteful number, since it uses less digits than its factorization.

13111640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2003 (or 1999 counting only the distinct ones).

The product of its (nonzero) digits is 72, while the sum is 17.

The square root of 13111640 is about 3620.9998619166. Note that the first 3 decimals coincide. The cubic root of 13111640 is about 235.8046357913.

Adding to 13111640 its reverse (4611131), we get a palindrome (17722771).

The spelling of 13111640 in words is "thirteen million, one hundred eleven thousand, six hundred forty".