13211820 has 72 divisors (see below), whose sum is σ = 41474160. Its totient is φ = 3400320.

The previous prime is 13211819. The next prime is 13211827. The reversal of 13211820 is 2811231.

It is a Harshad number since it is a multiple of its sum of digits (18).

It is a junction number, because it is equal to n+sod(n) for n = 13211793 and 13211802.

It is not an unprimeable number, because it can be changed into a prime (13211827) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 3955 + ... + 6485.

It is an arithmetic number, because the mean of its divisors is an integer number (576030).

Almost surely, 2^13211820 is an apocalyptic number.

13211820 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 13211820, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (20737080).

13211820 is an abundant number, since it is smaller than the sum of its proper divisors (28262340).

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

13211820 is a wasteful number, since it uses less digits than its factorization.

13211820 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2575 (or 2570 counting only the distinct ones).

The product of its (nonzero) digits is 96, while the sum is 18.

The square root of 13211820 is about 3634.8067348898. The cubic root of 13211820 is about 236.4036709128.

The spelling of 13211820 in words is "thirteen million, two hundred eleven thousand, eight hundred twenty".