121405121 has 2 divisors, whose sum is σ = 121405122. Its totient is φ = 121405120.

The previous prime is 121405093. The next prime is 121405129. The reversal of 121405121 is 121504121.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 119596096 + 1809025 = 10936^2 + 1345^2 .

It is an emirp because it is prime and its reverse (121504121) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 121405121 - 2¹⁸ = 121142977 is a prime.

It is a Chen prime.

It is a self number, because there is not a number n which added to its sum of digits gives 121405121.

It is not a weakly prime, because it can be changed into another prime (121405129) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 60702560 + 60702561.

It is an arithmetic number, because the mean of its divisors is an integer number (60702561).

Almost surely, 2^121405121 is an apocalyptic number.

It is an amenable number.

121405121 is a deficient number, since it is larger than the sum of its proper divisors (1).

121405121 is an equidigital number, since it uses as much as digits as its factorization.

121405121 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 80, while the sum is 17.

The square root of 121405121 is about 11018.3992031511. The cubic root of 121405121 is about 495.1601304872.

Adding to 121405121 its reverse (121504121), we get a palindrome (242909242).

The spelling of 121405121 in words is "one hundred twenty-one million, four hundred five thousand, one hundred twenty-one".