1331111220 has 48 divisors (see below), whose sum is σ = 3946356288. Its totient is φ = 334082560.

The previous prime is 1331111209. The next prime is 1331111227. The reversal of 1331111220 is 221111331.

It is a happy number.

It is a Harshad number since it is a multiple of its sum of digits (15).

It is a self number, because there is not a number n which added to its sum of digits gives 1331111220.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1331111227) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 651486 + ... + 653525.

It is an arithmetic number, because the mean of its divisors is an integer number (82215756).

Almost surely, 2^1331111220 is an apocalyptic number.

1331111220 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1331111220 is an abundant number, since it is smaller than the sum of its proper divisors (2615245068).

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

1331111220 is a wasteful number, since it uses less digits than its factorization.

1331111220 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1305040 (or 1305038 counting only the distinct ones).

The product of its (nonzero) digits is 36, while the sum is 15.

The square root of 1331111220 is about 36484.3969389656. The cubic root of 1331111220 is about 1100.0306382651.

Adding to 1331111220 its reverse (221111331), we get a palindrome (1552222551).

It can be divided in two parts, 1331111 and 220, that added together give a palindrome (1331331).

The spelling of 1331111220 in words is "one billion, three hundred thirty-one million, one hundred eleven thousand, two hundred twenty".