1331305220 has 24 divisors (see below), whose sum is σ = 3195132864. Its totient is φ = 456447456.

The previous prime is 1331305201. The next prime is 1331305229. The reversal of 1331305220 is 225031331.

It is a Harshad number since it is a multiple of its sum of digits (20).

It is a junction number, because it is equal to n+sod(n) for n = 1331305192 and 1331305201.

It is not an unprimeable number, because it can be changed into a prime (1331305229) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 4754522 + ... + 4754801.

It is an arithmetic number, because the mean of its divisors is an integer number (133130536).

Almost surely, 2^1331305220 is an apocalyptic number.

1331305220 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1331305220 is an abundant number, since it is smaller than the sum of its proper divisors (1863827644).

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

1331305220 is a wasteful number, since it uses less digits than its factorization.

1331305220 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9509339 (or 9509337 counting only the distinct ones).

The product of its (nonzero) digits is 540, while the sum is 20.

The square root of 1331305220 is about 36487.0555128802. The cubic root of 1331305220 is about 1100.0840762183.

Adding to 1331305220 its reverse (225031331), we get a palindrome (1556336551).

The spelling of 1331305220 in words is "one billion, three hundred thirty-one million, three hundred five thousand, two hundred twenty".