1091381243 has 2 divisors, whose sum is σ = 1091381244. Its totient is φ = 1091381242.

The previous prime is 1091381201. The next prime is 1091381251. The reversal of 1091381243 is 3421831901.

It is a strong prime.

It is an emirp because it is prime and its reverse (3421831901) is a distict prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1091381243 is a prime.

It is a super-2 number, since 2×1091381243² = 2382226035144450098, which contains 22 as substring.

It is a Sophie Germain prime.

It is not a weakly prime, because it can be changed into another prime (1091381843) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 545690621 + 545690622.

It is an arithmetic number, because the mean of its divisors is an integer number (545690622).

Almost surely, 2^1091381243 is an apocalyptic number.

1091381243 is a deficient number, since it is larger than the sum of its proper divisors (1).

1091381243 is an equidigital number, since it uses as much as digits as its factorization.

1091381243 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 5184, while the sum is 32.

The square root of 1091381243 is about 33036.0597378077. The cubic root of 1091381243 is about 1029.5769912849.

The spelling of 1091381243 in words is "one billion, ninety-one million, three hundred eighty-one thousand, two hundred forty-three".