121611643 has 2 divisors, whose sum is σ = 121611644. Its totient is φ = 121611642.

The previous prime is 121611641. The next prime is 121611653. The reversal of 121611643 is 346116121.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 121611643 - 2¹ = 121611641 is a prime.

Together with 121611641, it forms a pair of twin primes.

It is not a weakly prime, because it can be changed into another prime (121611641) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 60805821 + 60805822.

It is an arithmetic number, because the mean of its divisors is an integer number (60805822).

Almost surely, 2^121611643 is an apocalyptic number.

121611643 is a deficient number, since it is larger than the sum of its proper divisors (1).

121611643 is an equidigital number, since it uses as much as digits as its factorization.

121611643 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 864, while the sum is 25.

The square root of 121611643 is about 11027.7669090347. The cubic root of 121611643 is about 495.4407433882.

Adding to 121611643 its reverse (346116121), we get a palindrome (467727764).

The spelling of 121611643 in words is "one hundred twenty-one million, six hundred eleven thousand, six hundred forty-three".