1311122220 has 24 divisors (see below), whose sum is σ = 3671142384. Its totient is φ = 349632576.

The previous prime is 1311122207. The next prime is 1311122221. The reversal of 1311122220 is 222211131.

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 1311122220.

It is not an unprimeable number, because it can be changed into a prime (1311122221) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 10925959 + ... + 10926078.

It is an arithmetic number, because the mean of its divisors is an integer number (152964266).

Almost surely, 2^1311122220 is an apocalyptic number.

1311122220 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1311122220 is an abundant number, since it is smaller than the sum of its proper divisors (2360020164).

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

1311122220 is a wasteful number, since it uses less digits than its factorization.

1311122220 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 21852049 (or 21852047 counting only the distinct ones).

The product of its (nonzero) digits is 48, while the sum is 15.

The square root of 1311122220 is about 36209.4217020930. The cubic root of 1311122220 is about 1094.4965388457.

Adding to 1311122220 its reverse (222211131), we get a palindrome (1533333351).

The spelling of 1311122220 in words is "one billion, three hundred eleven million, one hundred twenty-two thousand, two hundred twenty".