11021020991 has 2 divisors, whose sum is σ = 11021020992. Its totient is φ = 11021020990.

The previous prime is 11021020987. The next prime is 11021021027. The reversal of 11021020991 is 19902012011.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 11021020991 - 2² = 11021020987 is a prime.

It is a super-3 number, since 3×11021020991³ (a number of 31 digits) contains 333 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 11021020991.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (11021020921) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5510510495 + 5510510496.

It is an arithmetic number, because the mean of its divisors is an integer number (5510510496).

Almost surely, 2^11021020991 is an apocalyptic number.

11021020991 is a deficient number, since it is larger than the sum of its proper divisors (1).

11021020991 is an equidigital number, since it uses as much as digits as its factorization.

11021020991 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 324, while the sum is 26.

It can be divided in two parts, 11021020 and 991, that added together give a palindrome (11022011).

The spelling of 11021020991 in words is "eleven billion, twenty-one million, twenty thousand, nine hundred ninety-one".