121931221 has 2 divisors, whose sum is σ = 121931222. Its totient is φ = 121931220.

The previous prime is 121931213. The next prime is 121931237. The reversal of 121931221 is 122139121.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 90459121 + 31472100 = 9511^2 + 5610^2 .

It is a cyclic number.

It is not a de Polignac number, because 121931221 - 2³ = 121931213 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 121931192 and 121931201.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (121931261) 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, 60965610 + 60965611.

It is an arithmetic number, because the mean of its divisors is an integer number (60965611).

Almost surely, 2^121931221 is an apocalyptic number.

It is an amenable number.

121931221 is a deficient number, since it is larger than the sum of its proper divisors (1).

121931221 is an equidigital number, since it uses as much as digits as its factorization.

121931221 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 216, while the sum is 22.

The square root of 121931221 is about 11042.2470992095. The cubic root of 121931221 is about 495.8743462595.

The spelling of 121931221 in words is "one hundred twenty-one million, nine hundred thirty-one thousand, two hundred twenty-one".