121215641 has 2 divisors, whose sum is σ = 121215642. Its totient is φ = 121215640.

The previous prime is 121215637. The next prime is 121215659. The reversal of 121215641 is 146512121.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 112805641 + 8410000 = 10621^2 + 2900^2 .

It is a cyclic number.

It is not a de Polignac number, because 121215641 - 2² = 121215637 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (121215631) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 60607820 + 60607821.

It is an arithmetic number, because the mean of its divisors is an integer number (60607821).

Almost surely, 2^121215641 is an apocalyptic number.

It is an amenable number.

121215641 is a deficient number, since it is larger than the sum of its proper divisors (1).

121215641 is an equidigital number, since it uses as much as digits as its factorization.

121215641 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 480, while the sum is 23.

The square root of 121215641 is about 11009.7975004084. The cubic root of 121215641 is about 494.9023934337.

Adding to 121215641 its reverse (146512121), we get a palindrome (267727762).

The spelling of 121215641 in words is "one hundred twenty-one million, two hundred fifteen thousand, six hundred forty-one".