11111009921 has 4 divisors (see below), whose sum is σ = 12121101744. Its totient is φ = 10100918100.

The previous prime is 11111009911. The next prime is 11111009927. The reversal of 11111009921 is 12990011111.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 11111009921 - 2⁶ = 11111009857 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (11111009927) 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 in 3 ways as a sum of consecutive naturals, for example, 505045895 + ... + 505045916.

It is an arithmetic number, because the mean of its divisors is an integer number (3030275436).

Almost surely, 2^11111009921 is an apocalyptic number.

11111009921 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

It is an amenable number.

11111009921 is a deficient number, since it is larger than the sum of its proper divisors (1010091823).

11111009921 is a wasteful number, since it uses less digits than its factorization.

11111009921 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1010091822.

The product of its (nonzero) digits is 162, while the sum is 26.

The spelling of 11111009921 in words is "eleven billion, one hundred eleven million, nine thousand, nine hundred twenty-one".