1320120521 has 4 divisors (see below), whose sum is σ = 1355799492. Its totient is φ = 1284441552.

The previous prime is 1320120509. The next prime is 1320120541. The reversal of 1320120521 is 1250210231.

It is a happy number.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 1158449296 + 161671225 = 34036^2 + 12715^2 .

It is a cyclic number.

It is not a de Polignac number, because 1320120521 - 2¹⁰ = 1320119497 is a prime.

It is a super-2 number, since 2×1320120521² = 3485436379930622882, which contains 22 as substring.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 1320120521.

It is not an unprimeable number, because it can be changed into a prime (1320120541) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 17839430 + ... + 17839503.

It is an arithmetic number, because the mean of its divisors is an integer number (338949873).

Almost surely, 2^1320120521 is an apocalyptic number.

It is an amenable number.

1320120521 is a deficient number, since it is larger than the sum of its proper divisors (35678971).

1320120521 is an equidigital number, since it uses as much as digits as its factorization.

1320120521 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 35678970.

The product of its (nonzero) digits is 120, while the sum is 17.

The square root of 1320120521 is about 36333.4628269864. The cubic root of 1320120521 is about 1096.9946950448.

Adding to 1320120521 its reverse (1250210231), we get a palindrome (2570330752).

The spelling of 1320120521 in words is "one billion, three hundred twenty million, one hundred twenty thousand, five hundred twenty-one".