121217641 has 2 divisors, whose sum is σ = 121217642. Its totient is φ = 121217640.

The previous prime is 121217639. The next prime is 121217669. The reversal of 121217641 is 146712121.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 94478400 + 26739241 = 9720^2 + 5171^2 .

It is an emirp because it is prime and its reverse (146712121) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 121217641 - 2¹ = 121217639 is a prime.

Together with 121217639, it forms a pair of twin primes.

It is a nialpdrome in base 15.

It is not a weakly prime, because it can be changed into another prime (121217141) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 60608820 + 60608821.

It is an arithmetic number, because the mean of its divisors is an integer number (60608821).

Almost surely, 2^121217641 is an apocalyptic number.

It is an amenable number.

121217641 is a deficient number, since it is larger than the sum of its proper divisors (1).

121217641 is an equidigital number, since it uses as much as digits as its factorization.

121217641 is an evil number, because the sum of its binary digits is even.

The product of its digits is 672, while the sum is 25.

The square root of 121217641 is about 11009.8883282257. Note that the first 3 decimals coincide. The cubic root of 121217641 is about 494.9051153028.

Adding to 121217641 its reverse (146712121), we get a palindrome (267929762).

The spelling of 121217641 in words is "one hundred twenty-one million, two hundred seventeen thousand, six hundred forty-one".