13121312220 has 288 divisors, whose sum is σ = 43512705600. Its totient is φ = 3189030912.

The previous prime is 13121312207. The next prime is 13121312299. The reversal of 13121312220 is 2221312131.

13121312220 is a `hidden beast` number, since 1 + 312 + 131 + 2 + 220 = 666.

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 = 13121312193 and 13121312202.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 12273846 + ... + 12274914.

Almost surely, 2^13121312220 is an apocalyptic number.

13121312220 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 13121312220, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (21756352800).

13121312220 is an abundant number, since it is smaller than the sum of its proper divisors (30391393380).

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

13121312220 is a wasteful number, since it uses less digits than its factorization.

13121312220 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1237 (or 1232 counting only the distinct ones).

The product of its (nonzero) digits is 144, while the sum is 18.

Adding to 13121312220 its reverse (2221312131), we get a palindrome (15342624351).

The spelling of 13121312220 in words is "thirteen billion, one hundred twenty-one million, three hundred twelve thousand, two hundred twenty".