1320002561321 has 4 divisors (see below), whose sum is σ = 1320009740112. Its totient is φ = 1319995382532.

The previous prime is 1320002561309. The next prime is 1320002561327. The reversal of 1320002561321 is 1231652000231.

It is a happy number.

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 a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1320002561321 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1320002561327) 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, 3306131 + ... + 3683816.

It is an arithmetic number, because the mean of its divisors is an integer number (330002435028).

Almost surely, 2^{1320002561321} is an apocalyptic number.

It is an amenable number.

1320002561321 is a deficient number, since it is larger than the sum of its proper divisors (7178791).

1320002561321 is an equidigital number, since it uses as much as digits as its factorization.

1320002561321 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7178790.

The product of its (nonzero) digits is 2160, while the sum is 26.

Adding to 1320002561321 its reverse (1231652000231), we get a palindrome (2551654561552).

The spelling of 1320002561321 in words is "one trillion, three hundred twenty billion, two million, five hundred sixty-one thousand, three hundred twenty-one".