1321100000 has 144 divisors (see below), whose sum is σ = 3549429072. Its totient is φ = 480000000.

The previous prime is 1321099993. The next prime is 1321100009. The reversal of 1321100000 is 11231.

It is a Harshad number since it is a multiple of its sum of digits (8).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1321100009) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 1099400 + ... + 1100600.

It is an arithmetic number, because the mean of its divisors is an integer number (24648813).

Almost surely, 2^1321100000 is an apocalyptic number.

1321100000 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 1321100000, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1774714536).

1321100000 is an abundant number, since it is smaller than the sum of its proper divisors (2228329072).

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

1321100000 is an equidigital number, since it uses as much as digits as its factorization.

1321100000 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1247 (or 1219 counting only the distinct ones).

The product of its (nonzero) digits is 6, while the sum is 8.

The square root of 1321100000 is about 36346.9393484513. The cubic root of 1321100000 is about 1097.2659373587.

Adding to 1321100000 its reverse (11231), we get a palindrome (1321111231).

The spelling of 1321100000 in words is "one billion, three hundred twenty-one million, one hundred thousand".