121215791 has 2 divisors, whose sum is σ = 121215792. Its totient is φ = 121215790.

The previous prime is 121215751. The next prime is 121215793. The reversal of 121215791 is 197512121.

It is a happy number.

It is a strong prime.

It is an emirp because it is prime and its reverse (197512121) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 121215791 - 2¹⁰ = 121214767 is a prime.

Together with 121215793, it forms a pair of twin primes.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (121215793) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 60607895 + 60607896.

It is an arithmetic number, because the mean of its divisors is an integer number (60607896).

Almost surely, 2^121215791 is an apocalyptic number.

121215791 is a deficient number, since it is larger than the sum of its proper divisors (1).

121215791 is an equidigital number, since it uses as much as digits as its factorization.

121215791 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 1260, while the sum is 29.

The square root of 121215791 is about 11009.8043125207. The cubic root of 121215791 is about 494.9025975749.

The spelling of 121215791 in words is "one hundred twenty-one million, two hundred fifteen thousand, seven hundred ninety-one".