18812127221 has 4 divisors (see below), whose sum is σ = 19802239200. Its totient is φ = 17822015244.

The previous prime is 18812127199. The next prime is 18812127311. The reversal of 18812127221 is 12272121881.

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 18812127221 - 2¹⁰ = 18812126197 is a prime.

It is a super-2 number, since 2×18812127221² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18812121221) by changing a digit.

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, 495055961 + ... + 495055998.

It is an arithmetic number, because the mean of its divisors is an integer number (4950559800).

Almost surely, 2^18812127221 is an apocalyptic number.

It is an amenable number.

18812127221 is a deficient number, since it is larger than the sum of its proper divisors (990111979).

18812127221 is an equidigital number, since it uses as much as digits as its factorization.

18812127221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 990111978.

The product of its digits is 7168, while the sum is 35.

The spelling of 18812127221 in words is "eighteen billion, eight hundred twelve million, one hundred twenty-seven thousand, two hundred twenty-one".