1266820871 has 2 divisors, whose sum is σ = 1266820872. Its totient is φ = 1266820870.

The previous prime is 1266820847. The next prime is 1266820879. The reversal of 1266820871 is 1780286621.

It is a strong prime.

It is an emirp because it is prime and its reverse (1780286621) is a distict prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1266820871 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1266820879) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 633410435 + 633410436.

It is an arithmetic number, because the mean of its divisors is an integer number (633410436).

Almost surely, 2^1266820871 is an apocalyptic number.

1266820871 is a deficient number, since it is larger than the sum of its proper divisors (1).

1266820871 is an equidigital number, since it uses as much as digits as its factorization.

1266820871 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 64512, while the sum is 41.

The square root of 1266820871 is about 35592.4271580346. The cubic root of 1266820871 is about 1082.0277607413.

The spelling of 1266820871 in words is "one billion, two hundred sixty-six million, eight hundred twenty thousand, eight hundred seventy-one".