10991900993 has 2 divisors, whose sum is σ = 10991900994. Its totient is φ = 10991900992.

The previous prime is 10991900989. The next prime is 10991901049. The reversal of 10991900993 is 39900919901.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 5520044209 + 5471856784 = 74297^2 + 73972^2 .

It is a cyclic number.

It is not a de Polignac number, because 10991900993 - 2² = 10991900989 is a prime.

It is not a weakly prime, because it can be changed into another prime (10991900923) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5495950496 + 5495950497.

It is an arithmetic number, because the mean of its divisors is an integer number (5495950497).

Almost surely, 2^10991900993 is an apocalyptic number.

It is an amenable number.

10991900993 is a deficient number, since it is larger than the sum of its proper divisors (1).

10991900993 is an equidigital number, since it uses as much as digits as its factorization.

10991900993 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 177147, while the sum is 50.

The spelling of 10991900993 in words is "ten billion, nine hundred ninety-one million, nine hundred thousand, nine hundred ninety-three".