13121033220 has 144 divisors (see below), whose sum is σ = 40459346928. Its totient is φ = 3441484800.

The previous prime is 13121033197. The next prime is 13121033221. The reversal of 13121033220 is 2233012131.

13121033220 is a `hidden beast` number, since 1 + 312 + 1 + 0 + 332 + 20 = 666.

It can be written as a sum of positive squares in 8 ways, for example, as 260112384 + 12860920836 = 16128^2 + 113406^2 .

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 = 13121033193 and 13121033202.

It is not an unprimeable number, because it can be changed into a prime (13121033221) 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 47 ways as a sum of consecutive naturals, for example, 2851962 + ... + 2856558.

It is an arithmetic number, because the mean of its divisors is an integer number (280967687).

Almost surely, 2^13121033220 is an apocalyptic number.

13121033220 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 13121033220, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (20229673464).

13121033220 is an abundant number, since it is smaller than the sum of its proper divisors (27338313708).

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

13121033220 is a wasteful number, since it uses less digits than its factorization.

13121033220 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4870 (or 4865 counting only the distinct ones).

The product of its (nonzero) digits is 216, while the sum is 18.

Adding to 13121033220 its reverse (2233012131), we get a palindrome (15354045351).

The spelling of 13121033220 in words is "thirteen billion, one hundred twenty-one million, thirty-three thousand, two hundred twenty".