121787221 has 2 divisors, whose sum is σ = 121787222. Its totient is φ = 121787220.

The previous prime is 121787203. The next prime is 121787233. The reversal of 121787221 is 122787121.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 87142225 + 34644996 = 9335^2 + 5886^2 .

It is an emirp because it is prime and its reverse (122787121) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 121787221 - 2¹¹ = 121785173 is a prime.

It is equal to p_6937600 and since 121787221 and 6937600 have the same sum of digits, it is a Honaker prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (121787021) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 60893610 + 60893611.

It is an arithmetic number, because the mean of its divisors is an integer number (60893611).

Almost surely, 2^121787221 is an apocalyptic number.

It is an amenable number.

121787221 is a deficient number, since it is larger than the sum of its proper divisors (1).

121787221 is an equidigital number, since it uses as much as digits as its factorization.

121787221 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 3136, while the sum is 31.

The square root of 121787221 is about 11035.7247609751. The cubic root of 121787221 is about 495.6790612081.

The spelling of 121787221 in words is "one hundred twenty-one million, seven hundred eighty-seven thousand, two hundred twenty-one".