1321505011 has 4 divisors (see below), whose sum is σ = 1335128872. Its totient is φ = 1307881152.

The previous prime is 1321504981. The next prime is 1321505033. The reversal of 1321505011 is 1105051231.

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1321505011 is a prime.

It is a super-2 number, since 2×1321505011² = 3492750988196220242, 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 1321505011.

It is not an unprimeable number, because it can be changed into a prime (1321502011) 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, 6811785 + ... + 6811978.

It is an arithmetic number, because the mean of its divisors is an integer number (333782218).

Almost surely, 2^1321505011 is an apocalyptic number.

1321505011 is a deficient number, since it is larger than the sum of its proper divisors (13623861).

1321505011 is an equidigital number, since it uses as much as digits as its factorization.

1321505011 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 13623860.

The product of its (nonzero) digits is 150, while the sum is 19.

The square root of 1321505011 is about 36352.5103809902. The cubic root of 1321505011 is about 1097.3780558884.

Adding to 1321505011 its reverse (1105051231), we get a palindrome (2426556242).

The spelling of 1321505011 in words is "one billion, three hundred twenty-one million, five hundred five thousand, eleven".