1291964381 has 2 divisors, whose sum is σ = 1291964382. Its totient is φ = 1291964380.

The previous prime is 1291964363. The next prime is 1291964431. The reversal of 1291964381 is 1834691921.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 969761881 + 322202500 = 31141^2 + 17950^2 .

It is an emirp because it is prime and its reverse (1834691921) is a distict prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1291964381 is a prime.

It is a super-2 number, since 2×1291964381² = 3338343923545426322, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1291964281) 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 as a sum of consecutive naturals, namely, 645982190 + 645982191.

It is an arithmetic number, because the mean of its divisors is an integer number (645982191).

Almost surely, 2^1291964381 is an apocalyptic number.

It is an amenable number.

1291964381 is a deficient number, since it is larger than the sum of its proper divisors (1).

1291964381 is an equidigital number, since it uses as much as digits as its factorization.

1291964381 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 93312, while the sum is 44.

The square root of 1291964381 is about 35943.9060342640. The cubic root of 1291964381 is about 1089.1395113756.

The spelling of 1291964381 in words is "one billion, two hundred ninety-one million, nine hundred sixty-four thousand, three hundred eighty-one".