13611640 has 64 divisors (see below), whose sum is σ = 35328960. Its totient is φ = 4623360.

The previous prime is 13611613. The next prime is 13611659. The reversal of 13611640 is 4611631.

13611640 = T₁₆₀ + T₁₆₁ + ... + T₄₄₀.

It is a happy number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 48300 + ... + 48580.

It is an arithmetic number, because the mean of its divisors is an integer number (552015).

Almost surely, 2^13611640 is an apocalyptic number.

13611640 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 13611640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (17664480).

13611640 is an abundant number, since it is smaller than the sum of its proper divisors (21717320).

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

13611640 is a wasteful number, since it uses less digits than its factorization.

13611640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 472 (or 468 counting only the distinct ones).

The product of its (nonzero) digits is 432, while the sum is 22.

The square root of 13611640 is about 3689.3956144604. The cubic root of 13611640 is about 238.7647177134.

Subtracting from 13611640 its reverse (4611631), we obtain a palindrome (9000009).

The spelling of 13611640 in words is "thirteen million, six hundred eleven thousand, six hundred forty".