121220111220218 has 4 divisors (see below), whose sum is σ = 181830166830330. Its totient is φ = 60610055610108.

The previous prime is 121220111220217. The next prime is 121220111220227. The reversal of 121220111220218 is 812022111022121.

It is a happy number.

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

It can be written as a sum of positive squares in only one way, i.e., 113724031237609 + 7496079982609 = 10664147^2 + 2737897^2 .

It is not an unprimeable number, because it can be changed into a prime (121220111220217) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 30305027805053 + ... + 30305027805056.

Almost surely, 2^{121220111220218} is an apocalyptic number.

121220111220218 is a deficient number, since it is larger than the sum of its proper divisors (60610055610112).

121220111220218 is an equidigital number, since it uses as much as digits as its factorization.

121220111220218 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 60610055610111.

The product of its (nonzero) digits is 512, while the sum is 26.

Adding to 121220111220218 its reverse (812022111022121), we get a palindrome (933242222242339).

The spelling of 121220111220218 in words is "one hundred twenty-one trillion, two hundred twenty billion, one hundred eleven million, two hundred twenty thousand, two hundred eighteen".