1331020231 has 4 divisors (see below), whose sum is σ = 1332779272. Its totient is φ = 1329261192.

The previous prime is 1331020211. The next prime is 1331020259. The reversal of 1331020231 is 1320201331.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 1320201331 = 97 ⋅13610323.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1331020231 is a prime.

It is a super-2 number, since 2×1331020231² = 3543229710662586722, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1331020211) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 878385 + ... + 879898.

It is an arithmetic number, because the mean of its divisors is an integer number (333194818).

Almost surely, 2^1331020231 is an apocalyptic number.

1331020231 is a deficient number, since it is larger than the sum of its proper divisors (1759041).

1331020231 is an equidigital number, since it uses as much as digits as its factorization.

1331020231 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1759040.

The product of its (nonzero) digits is 108, while the sum is 16.

The square root of 1331020231 is about 36483.1499599473. The cubic root of 1331020231 is about 1100.0055732500.

Adding to 1331020231 its reverse (1320201331), we get a palindrome (2651221562).

The spelling of 1331020231 in words is "one billion, three hundred thirty-one million, twenty thousand, two hundred thirty-one".