1320065553 has 4 divisors (see below), whose sum is σ = 1760087408. Its totient is φ = 880043700.

The previous prime is 1320065501. The next prime is 1320065563. The reversal of 1320065553 is 3555600231.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is not a de Polignac number, because 1320065553 - 2²⁶ = 1252956689 is a prime.

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 1320065553.

It is not an unprimeable number, because it can be changed into a prime (1320065563) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 220010923 + ... + 220010928.

It is an arithmetic number, because the mean of its divisors is an integer number (440021852).

Almost surely, 2^1320065553 is an apocalyptic number.

It is an amenable number.

1320065553 is a deficient number, since it is larger than the sum of its proper divisors (440021855).

1320065553 is an equidigital number, since it uses as much as digits as its factorization.

1320065553 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 440021854.

The product of its (nonzero) digits is 13500, while the sum is 30.

The square root of 1320065553 is about 36332.7063814410. The cubic root of 1320065553 is about 1096.9794690508.

Adding to 1320065553 its reverse (3555600231), we get a palindrome (4875665784).

The spelling of 1320065553 in words is "one billion, three hundred twenty million, sixty-five thousand, five hundred fifty-three".