1331991347 has 2 divisors, whose sum is σ = 1331991348. Its totient is φ = 1331991346.

The previous prime is 1331991343. The next prime is 1331991391. The reversal of 1331991347 is 7431991331.

It is a weak prime.

It is an emirp because it is prime and its reverse (7431991331) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 1331991347 - 2² = 1331991343 is a prime.

It is not a weakly prime, because it can be changed into another prime (1331991343) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 665995673 + 665995674.

It is an arithmetic number, because the mean of its divisors is an integer number (665995674).

Almost surely, 2^1331991347 is an apocalyptic number.

1331991347 is a deficient number, since it is larger than the sum of its proper divisors (1).

1331991347 is an equidigital number, since it uses as much as digits as its factorization.

1331991347 is an evil number, because the sum of its binary digits is even.

The product of its digits is 61236, while the sum is 41.

The square root of 1331991347 is about 36496.4566362270. The cubic root of 1331991347 is about 1100.2730305727.

The spelling of 1331991347 in words is "one billion, three hundred thirty-one million, nine hundred ninety-one thousand, three hundred forty-seven".