1311013121220 has 288 divisors, whose sum is σ = 4485452025600. Its totient is φ = 307153658880.

The previous prime is 1311013121219. The next prime is 1311013121287. The reversal of 1311013121220 is 221213101131.

1311013121220 is a `hidden beast` number, since 1 + 31 + 101 + 312 + 1 + 220 = 666.

It is a super-2 number, since 2×1311013121220² (a number of 25 digits) contains 22 as substring.

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 = 1311013121193 and 1311013121202.

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, 10855689 + ... + 10975791.

It is an arithmetic number, because the mean of its divisors is an integer number (15574486200).

Almost surely, 2^{1311013121220} is an apocalyptic number.

1311013121220 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 1311013121220, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2242726012800).

1311013121220 is an abundant number, since it is smaller than the sum of its proper divisors (3174438904380).

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

1311013121220 is a wasteful number, since it uses less digits than its factorization.

1311013121220 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 120315 (or 120310 counting only the distinct ones).

The product of its (nonzero) digits is 72, while the sum is 18.

Adding to 1311013121220 its reverse (221213101131), we get a palindrome (1532226222351).

The spelling of 1311013121220 in words is "one trillion, three hundred eleven billion, thirteen million, one hundred twenty-one thousand, two hundred twenty".