1321201331 has 4 divisors (see below), whose sum is σ = 1346129712. Its totient is φ = 1296272952.

The previous prime is 1321201303. The next prime is 1321201339. The reversal of 1321201331 is 1331021231.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 1331021231 = 19 ⋅70053749.

It is a cyclic number.

It is not a de Polignac number, because 1321201331 - 2⁶ = 1321201267 is a prime.

It is a super-2 number, since 2×1321201331² = 3491145914072343122, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1321201339) 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, 12464111 + ... + 12464216.

It is an arithmetic number, because the mean of its divisors is an integer number (336532428).

Almost surely, 2^1321201331 is an apocalyptic number.

1321201331 is a deficient number, since it is larger than the sum of its proper divisors (24928381).

1321201331 is an equidigital number, since it uses as much as digits as its factorization.

1321201331 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 24928380.

The product of its (nonzero) digits is 108, while the sum is 17.

The square root of 1321201331 is about 36348.3332630260. Note that the first 3 decimals coincide. The cubic root of 1321201331 is about 1097.2939908021.

Adding to 1321201331 its reverse (1331021231), we get a palindrome (2652222562).

The spelling of 1321201331 in words is "one billion, three hundred twenty-one million, two hundred one thousand, three hundred thirty-one".