1320813649 has 3 divisors (see below), whose sum is σ = 1320849993. Its totient is φ = 1320777306.

The previous prime is 1320813607. The next prime is 1320813661. The reversal of 1320813649 is 9463180231.

The square root of 1320813649 is 36343.

It is a perfect power (a square), and thus also a powerful number.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length, and also an emirpimes, since its reverse is a distinct semiprime: 9463180231 = 1549 ⋅6109219.

It is not a de Polignac number, because 1320813649 - 2¹¹ = 1320811601 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1320813049) 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 2 ways as a sum of consecutive naturals, for example, 18172 + ... + 54514.

It is an arithmetic number, because the mean of its divisors is an integer number (440283331).

Almost surely, 2^1320813649 is an apocalyptic number.

1320813649 is the 36343-rd square number.

1320813649 is the 18172-nd centered octagonal number.

It is an amenable number.

1320813649 is a deficient number, since it is larger than the sum of its proper divisors (36344).

1320813649 is an frugal number, since it uses more digits than its factorization.

1320813649 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 72686 (or 36343 counting only the distinct ones).

The product of its (nonzero) digits is 31104, while the sum is 37.

The cubic root of 1320813649 is about 1097.1866534533.

The spelling of 1320813649 in words is "one billion, three hundred twenty million, eight hundred thirteen thousand, six hundred forty-nine".