120755561 has 2 divisors, whose sum is σ = 120755562. Its totient is φ = 120755560.

The previous prime is 120755513. The next prime is 120755563. The reversal of 120755561 is 165557021.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 109599961 + 11155600 = 10469^2 + 3340^2 .

It is a cyclic number.

It is not a de Polignac number, because 120755561 - 2¹⁰ = 120754537 is a prime.

Together with 120755563, it forms a pair of twin primes.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (120755563) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 60377780 + 60377781.

It is an arithmetic number, because the mean of its divisors is an integer number (60377781).

Almost surely, 2^120755561 is an apocalyptic number.

It is an amenable number.

120755561 is a deficient number, since it is larger than the sum of its proper divisors (1).

120755561 is an equidigital number, since it uses as much as digits as its factorization.

120755561 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 10500, while the sum is 32.

The square root of 120755561 is about 10988.8835192662. The cubic root of 120755561 is about 494.2754573502.

The spelling of 120755561 in words is "one hundred twenty million, seven hundred fifty-five thousand, five hundred sixty-one".