1320021220 has 48 divisors (see below), whose sum is σ = 3198843648. Its totient is φ = 448179840.

The previous prime is 1320021169. The next prime is 1320021289. The reversal of 1320021220 is 221200231.

It is a self number, because there is not a number n which added to its sum of digits gives 1320021220.

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, 31351 + ... + 60190.

It is an arithmetic number, because the mean of its divisors is an integer number (66642576).

Almost surely, 2^1320021220 is an apocalyptic number.

1320021220 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1320021220 is an abundant number, since it is smaller than the sum of its proper divisors (1878822428).

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

1320021220 is a wasteful number, since it uses less digits than its factorization.

1320021220 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 91660 (or 91658 counting only the distinct ones).

The product of its (nonzero) digits is 48, while the sum is 13.

The square root of 1320021220 is about 36332.0962786350. The cubic root of 1320021220 is about 1096.9671886164.

Adding to 1320021220 its reverse (221200231), we get a palindrome (1541221451).

The spelling of 1320021220 in words is "one billion, three hundred twenty million, twenty-one thousand, two hundred twenty".