11110991221 has 4 divisors (see below), whose sum is σ = 12121081344. Its totient is φ = 10100901100.

The previous prime is 11110991219. The next prime is 11110991233. The reversal of 11110991221 is 12219901111.

It is a happy number.

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 11110991221 - 2¹ = 11110991219 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 11110991221.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (11110991251) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 505045045 + ... + 505045066.

It is an arithmetic number, because the mean of its divisors is an integer number (3030270336).

Almost surely, 2^11110991221 is an apocalyptic number.

11110991221 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

It is an amenable number.

11110991221 is a deficient number, since it is larger than the sum of its proper divisors (1010090123).

11110991221 is a wasteful number, since it uses less digits than its factorization.

11110991221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1010090122.

The product of its (nonzero) digits is 324, while the sum is 28.

The spelling of 11110991221 in words is "eleven billion, one hundred ten million, nine hundred ninety-one thousand, two hundred twenty-one".