1321220000 has 120 divisors (see below), whose sum is σ = 3356825472. Its totient is φ = 511200000.

The previous prime is 1321219997. The next prime is 1321220003. The reversal of 1321220000 is 221231.

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (1321219997) and next prime (1321220003).

It is not an unprimeable number, because it can be changed into a prime (1321220003) 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 19 ways as a sum of consecutive naturals, for example, 618935 + ... + 621065.

Almost surely, 2^1321220000 is an apocalyptic number.

1321220000 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 1321220000, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1678412736).

1321220000 is an abundant number, since it is smaller than the sum of its proper divisors (2035605472).

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

1321220000 is an equidigital number, since it uses as much as digits as its factorization.

1321220000 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2192 (or 2169 counting only the distinct ones).

The product of its (nonzero) digits is 24, while the sum is 11.

The square root of 1321220000 is about 36348.5900689422. The cubic root of 1321220000 is about 1097.2991591502.

Adding to 1321220000 its reverse (221231), we get a palindrome (1321441231).

The spelling of 1321220000 in words is "one billion, three hundred twenty-one million, two hundred twenty thousand".