1311818220 has 48 divisors (see below), whose sum is σ = 4081213920. Its totient is φ = 349818048.

The previous prime is 1311818171. The next prime is 1311818231. The reversal of 1311818220 is 228181131.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1214107 + ... + 1215186.

It is an arithmetic number, because the mean of its divisors is an integer number (85025290).

Almost surely, 2^1311818220 is an apocalyptic number.

1311818220 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1311818220 is an abundant number, since it is smaller than the sum of its proper divisors (2769395700).

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

1311818220 is a wasteful number, since it uses less digits than its factorization.

1311818220 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2429311 (or 2429303 counting only the distinct ones).

The product of its (nonzero) digits is 768, while the sum is 27.

The square root of 1311818220 is about 36219.0311852761. The cubic root of 1311818220 is about 1094.6901731807.

Adding to 1311818220 its reverse (228181131), we get a palindrome (1539999351).

The spelling of 1311818220 in words is "one billion, three hundred eleven million, eight hundred eighteen thousand, two hundred twenty".