1320357720 has 128 divisors (see below), whose sum is σ = 4370112000. Its totient is φ = 316462080.

The previous prime is 1320357697. The next prime is 1320357737. The reversal of 1320357720 is 277530231.

It is a Harshad number since it is a multiple of its sum of digits (30).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 111861 + ... + 123099.

It is an arithmetic number, because the mean of its divisors is an integer number (34141500).

Almost surely, 2^1320357720 is an apocalyptic number.

1320357720 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 1320357720, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2185056000).

1320357720 is an abundant number, since it is smaller than the sum of its proper divisors (3049754280).

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

1320357720 is a wasteful number, since it uses less digits than its factorization.

1320357720 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 11353 (or 11349 counting only the distinct ones).

The product of its (nonzero) digits is 8820, while the sum is 30.

The square root of 1320357720 is about 36336.7268751603. The cubic root of 1320357720 is about 1097.0603937083.

Adding to 1320357720 its reverse (277530231), we get a palindrome (1597887951).

The spelling of 1320357720 in words is "one billion, three hundred twenty million, three hundred fifty-seven thousand, seven hundred twenty".