13821660 has 72 divisors (see below), whose sum is σ = 43295616. Its totient is φ = 3565440.

The previous prime is 13821659. The next prime is 13821667. The reversal of 13821660 is 6612831.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (13821667) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 4342 + ... + 6818.

It is an arithmetic number, because the mean of its divisors is an integer number (601328).

Almost surely, 2^13821660 is an apocalyptic number.

13821660 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 13821660, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (21647808).

13821660 is an abundant number, since it is smaller than the sum of its proper divisors (29473956).

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

13821660 is a wasteful number, since it uses less digits than its factorization.

13821660 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2523 (or 2518 counting only the distinct ones).

The product of its (nonzero) digits is 1728, while the sum is 27.

The square root of 13821660 is about 3717.7493191446. The cubic root of 13821660 is about 239.9864575692.

The spelling of 13821660 in words is "thirteen million, eight hundred twenty-one thousand, six hundred sixty".