118221221 has 2 divisors, whose sum is σ = 118221222. Its totient is φ = 118221220.

The previous prime is 118221167. The next prime is 118221223. The reversal of 118221221 is 122122811.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 95277121 + 22944100 = 9761^2 + 4790^2 .

It is a cyclic number.

It is not a de Polignac number, because 118221221 - 2²² = 114026917 is a prime.

Together with 118221223, it forms a pair of twin primes.

It is a Chen prime.

It is a junction number, because it is equal to n+sod(n) for n = 118221193 and 118221202.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (118221223) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 59110610 + 59110611.

It is an arithmetic number, because the mean of its divisors is an integer number (59110611).

Almost surely, 2^118221221 is an apocalyptic number.

It is an amenable number.

118221221 is a deficient number, since it is larger than the sum of its proper divisors (1).

118221221 is an equidigital number, since it uses as much as digits as its factorization.

118221221 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 128, while the sum is 20.

The square root of 118221221 is about 10872.9582451143. The cubic root of 118221221 is about 490.7931358826.

The spelling of 118221221 in words is "one hundred eighteen million, two hundred twenty-one thousand, two hundred twenty-one".