1261782911 has 2 divisors, whose sum is σ = 1261782912. Its totient is φ = 1261782910.

The previous prime is 1261782883. The next prime is 1261782937. The reversal of 1261782911 is 1192871621.

It is a strong prime.

It is an emirp because it is prime and its reverse (1192871621) is a distict prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1261782911 is a prime.

It is a super-2 number, since 2×1261782911² = 3184192228983267842, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1261782311) 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, 630891455 + 630891456.

It is an arithmetic number, because the mean of its divisors is an integer number (630891456).

Almost surely, 2^1261782911 is an apocalyptic number.

1261782911 is a deficient number, since it is larger than the sum of its proper divisors (1).

1261782911 is an equidigital number, since it uses as much as digits as its factorization.

1261782911 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 12096, while the sum is 38.

The square root of 1261782911 is about 35521.5837344001. The cubic root of 1261782911 is about 1080.5915001162.

The spelling of 1261782911 in words is "one billion, two hundred sixty-one million, seven hundred eighty-two thousand, nine hundred eleven".