121321691 has 2 divisors, whose sum is σ = 121321692. Its totient is φ = 121321690.

The previous prime is 121321679. The next prime is 121321723. The reversal of 121321691 is 196123121.

It is a weak prime.

It is an emirp because it is prime and its reverse (196123121) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 121321691 - 2²⁶ = 54212827 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 121321691.

It is not a weakly prime, because it can be changed into another prime (121321621) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 60660845 + 60660846.

It is an arithmetic number, because the mean of its divisors is an integer number (60660846).

Almost surely, 2^121321691 is an apocalyptic number.

121321691 is a deficient number, since it is larger than the sum of its proper divisors (1).

121321691 is an equidigital number, since it uses as much as digits as its factorization.

121321691 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 648, while the sum is 26.

The square root of 121321691 is about 11014.6126123437. The cubic root of 121321691 is about 495.0466792697.

The spelling of 121321691 in words is "one hundred twenty-one million, three hundred twenty-one thousand, six hundred ninety-one".