1331155439 has 2 divisors, whose sum is σ = 1331155440. Its totient is φ = 1331155438.

The previous prime is 1331155393. The next prime is 1331155489. The reversal of 1331155439 is 9345511331.

It is a weak prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1331155439 is a prime.

It is a Sophie Germain prime.

It is a junction number, because it is equal to n+sod(n) for n = 1331155399 and 1331155408.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1331155489) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 665577719 + 665577720.

It is an arithmetic number, because the mean of its divisors is an integer number (665577720).

Almost surely, 2^1331155439 is an apocalyptic number.

1331155439 is a deficient number, since it is larger than the sum of its proper divisors (1).

1331155439 is an equidigital number, since it uses as much as digits as its factorization.

1331155439 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 24300, while the sum is 35.

The square root of 1331155439 is about 36485.0029327120. The cubic root of 1331155439 is about 1100.0428189943.

The spelling of 1331155439 in words is "one billion, three hundred thirty-one million, one hundred fifty-five thousand, four hundred thirty-nine".