1331378791 has 2 divisors, whose sum is σ = 1331378792. Its totient is φ = 1331378790.

The previous prime is 1331378767. The next prime is 1331378821. The reversal of 1331378791 is 1978731331.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 1331378791 - 2¹⁷ = 1331247719 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1331370791) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 665689395 + 665689396.

It is an arithmetic number, because the mean of its divisors is an integer number (665689396).

Almost surely, 2^1331378791 is an apocalyptic number.

1331378791 is a deficient number, since it is larger than the sum of its proper divisors (1).

1331378791 is an equidigital number, since it uses as much as digits as its factorization.

1331378791 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 95256, while the sum is 43.

The square root of 1331378791 is about 36488.0636784141. The cubic root of 1331378791 is about 1100.1043402403.

The spelling of 1331378791 in words is "one billion, three hundred thirty-one million, three hundred seventy-eight thousand, seven hundred ninety-one".