11218917921 has 4 divisors (see below), whose sum is σ = 14958557232. Its totient is φ = 7479278612.

The previous prime is 11218917833. The next prime is 11218917929. The reversal of 11218917921 is 12971981211.

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 11218917921 - 2¹⁴ = 11218901537 is a prime.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (11218917929) 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, 1869819651 + ... + 1869819656.

It is an arithmetic number, because the mean of its divisors is an integer number (3739639308).

Almost surely, 2^11218917921 is an apocalyptic number.

It is an amenable number.

11218917921 is a deficient number, since it is larger than the sum of its proper divisors (3739639311).

11218917921 is an equidigital number, since it uses as much as digits as its factorization.

11218917921 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3739639310.

The product of its digits is 18144, while the sum is 42.

The spelling of 11218917921 in words is "eleven billion, two hundred eighteen million, nine hundred seventeen thousand, nine hundred twenty-one".