121557911 has 2 divisors, whose sum is σ = 121557912. Its totient is φ = 121557910.

The previous prime is 121557889. The next prime is 121557929. The reversal of 121557911 is 119755121.

It is a happy number.

It is a strong prime.

It is an emirp because it is prime and its reverse (119755121) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 121557911 - 2¹⁰ = 121556887 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (121557941) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 60778955 + 60778956.

It is an arithmetic number, because the mean of its divisors is an integer number (60778956).

Almost surely, 2^121557911 is an apocalyptic number.

121557911 is a deficient number, since it is larger than the sum of its proper divisors (1).

121557911 is an equidigital number, since it uses as much as digits as its factorization.

121557911 is an evil number, because the sum of its binary digits is even.

The product of its digits is 3150, while the sum is 32.

The square root of 121557911 is about 11025.3304258875. The cubic root of 121557911 is about 495.3677653328.

The spelling of 121557911 in words is "one hundred twenty-one million, five hundred fifty-seven thousand, nine hundred eleven".