11111221405 has 4 divisors (see below), whose sum is σ = 13333465692. Its totient is φ = 8888977120.

The previous prime is 11111221391. The next prime is 11111221423. The reversal of 11111221405 is 50412211111.

11111221405 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 8655325156 + 2455896249 = 93034^2 + 49557^2 .

It is not a de Polignac number, because 11111221405 - 2¹⁵ = 11111188637 is a prime.

It is a super-2 number, since 2×11111221405² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1111122136 + ... + 1111122145.

It is an arithmetic number, because the mean of its divisors is an integer number (3333366423).

Almost surely, 2^11111221405 is an apocalyptic number.

It is an amenable number.

11111221405 is a deficient number, since it is larger than the sum of its proper divisors (2222244287).

11111221405 is an equidigital number, since it uses as much as digits as its factorization.

11111221405 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2222244286.

The product of its (nonzero) digits is 80, while the sum is 19.

Adding to 11111221405 its reverse (50412211111), we get a palindrome (61523432516).

The spelling of 11111221405 in words is "eleven billion, one hundred eleven million, two hundred twenty-one thousand, four hundred five".