10991569871 has 2 divisors, whose sum is σ = 10991569872. Its totient is φ = 10991569870.

The previous prime is 10991569859. The next prime is 10991569949. The reversal of 10991569871 is 17896519901.

It is a weak prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-10991569871 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (10991569801) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5495784935 + 5495784936.

It is an arithmetic number, because the mean of its divisors is an integer number (5495784936).

Almost surely, 2^10991569871 is an apocalyptic number.

10991569871 is a deficient number, since it is larger than the sum of its proper divisors (1).

10991569871 is an equidigital number, since it uses as much as digits as its factorization.

10991569871 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 1224720, while the sum is 56.

The spelling of 10991569871 in words is "ten billion, nine hundred ninety-one million, five hundred sixty-nine thousand, eight hundred seventy-one".