1218352235221 has 4 divisors (see below), whose sum is σ = 1329111529344. Its totient is φ = 1107592941100.

The previous prime is 1218352235209. The next prime is 1218352235237. The reversal of 1218352235221 is 1225322538121.

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 1218352235221 - 2⁹ = 1218352234709 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1218352235251) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 55379647045 + ... + 55379647066.

It is an arithmetic number, because the mean of its divisors is an integer number (332277882336).

Almost surely, 2^{1218352235221} is an apocalyptic number.

1218352235221 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

It is an amenable number.

1218352235221 is a deficient number, since it is larger than the sum of its proper divisors (110759294123).

1218352235221 is a wasteful number, since it uses less digits than its factorization.

1218352235221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 110759294122.

The product of its digits is 57600, while the sum is 37.

The spelling of 1218352235221 in words is "one trillion, two hundred eighteen billion, three hundred fifty-two million, two hundred thirty-five thousand, two hundred twenty-one".