1331012321 has 4 divisors (see below), whose sum is σ = 1331105472. Its totient is φ = 1330919172.

The previous prime is 1331012273. The next prime is 1331012327. The reversal of 1331012321 is 1232101331.

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: 1232101331 = 461 ⋅2672671.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1331012321 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 1331012321.

It is not an unprimeable number, because it can be changed into a prime (1331012327) 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, 20141 + ... + 55386.

It is an arithmetic number, because the mean of its divisors is an integer number (332776368).

Almost surely, 2^1331012321 is an apocalyptic number.

It is an amenable number.

1331012321 is a deficient number, since it is larger than the sum of its proper divisors (93151).

1331012321 is an equidigital number, since it uses as much as digits as its factorization.

1331012321 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 93150.

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

The square root of 1331012321 is about 36483.0415535766. The cubic root of 1331012321 is about 1100.0033942044.

Adding to 1331012321 its reverse (1232101331), we get a palindrome (2563113652).

The spelling of 1331012321 in words is "one billion, three hundred thirty-one million, twelve thousand, three hundred twenty-one".