1331020291 has 2 divisors, whose sum is σ = 1331020292. Its totient is φ = 1331020290.

The previous prime is 1331020289. The next prime is 1331020303. The reversal of 1331020291 is 1920201331.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 1331020291 - 2¹ = 1331020289 is a prime.

Together with 1331020289, it forms a pair of twin primes.

It is not a weakly prime, because it can be changed into another prime (1331020211) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 665510145 + 665510146.

It is an arithmetic number, because the mean of its divisors is an integer number (665510146).

Almost surely, 2^1331020291 is an apocalyptic number.

1331020291 is a deficient number, since it is larger than the sum of its proper divisors (1).

1331020291 is an equidigital number, since it uses as much as digits as its factorization.

1331020291 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 324, while the sum is 22.

The square root of 1331020291 is about 36483.1507822447. The cubic root of 1331020291 is about 1100.0055897788.

The spelling of 1331020291 in words is "one billion, three hundred thirty-one million, twenty thousand, two hundred ninety-one".