121570991 has 2 divisors, whose sum is σ = 121570992. Its totient is φ = 121570990.

The previous prime is 121570979. The next prime is 121570993. The reversal of 121570991 is 199075121.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-121570991 is a prime.

Together with 121570993, it forms a pair of twin primes.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (121570993) 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, 60785495 + 60785496.

It is an arithmetic number, because the mean of its divisors is an integer number (60785496).

Almost surely, 2^121570991 is an apocalyptic number.

121570991 is a deficient number, since it is larger than the sum of its proper divisors (1).

121570991 is an equidigital number, since it uses as much as digits as its factorization.

121570991 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 5670, while the sum is 35.

The square root of 121570991 is about 11025.9235894323. The cubic root of 121570991 is about 495.3855323870.

The spelling of 121570991 in words is "one hundred twenty-one million, five hundred seventy thousand, nine hundred ninety-one".