121217251 has 2 divisors, whose sum is σ = 121217252. Its totient is φ = 121217250.

The previous prime is 121217249. The next prime is 121217263. The reversal of 121217251 is 152712121.

It is a weak prime.

It is an emirp because it is prime and its reverse (152712121) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 121217251 - 2¹ = 121217249 is a prime.

Together with 121217249, it forms a pair of twin primes.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (121217231) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 60608625 + 60608626.

It is an arithmetic number, because the mean of its divisors is an integer number (60608626).

Almost surely, 2^121217251 is an apocalyptic number.

121217251 is a deficient number, since it is larger than the sum of its proper divisors (1).

121217251 is an equidigital number, since it uses as much as digits as its factorization.

121217251 is an evil number, because the sum of its binary digits is even.

The product of its digits is 280, while the sum is 22.

The square root of 121217251 is about 11009.8706168601. The cubic root of 121217251 is about 494.9045845407.

Adding to 121217251 its reverse (152712121), we get a palindrome (273929372).

The spelling of 121217251 in words is "one hundred twenty-one million, two hundred seventeen thousand, two hundred fifty-one".