1320021121 has 4 divisors (see below), whose sum is σ = 1320094512. Its totient is φ = 1319947732.

The previous prime is 1320021097. The next prime is 1320021149. The reversal of 1320021121 is 1211200231.

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, and also a brilliant number, because the two primes have the same length, and also an emirpimes, since its reverse is a distinct semiprime: 1211200231 = 5927 ⋅204353.

It is a cyclic number.

It is not a de Polignac number, because 1320021121 - 2⁷ = 1320020993 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1320021161) 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, 10626 + ... + 52468.

It is an arithmetic number, because the mean of its divisors is an integer number (330023628).

Almost surely, 2^1320021121 is an apocalyptic number.

It is an amenable number.

1320021121 is a deficient number, since it is larger than the sum of its proper divisors (73391).

1320021121 is an equidigital number, since it uses as much as digits as its factorization.

1320021121 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 73390.

The product of its (nonzero) digits is 24, while the sum is 13.

The square root of 1320021121 is about 36332.0949162032. The cubic root of 1320021121 is about 1096.9671611927.

Adding to 1320021121 its reverse (1211200231), we get a palindrome (2531221352).

The spelling of 1320021121 in words is "one billion, three hundred twenty million, twenty-one thousand, one hundred twenty-one".