121905557 has 2 divisors, whose sum is σ = 121905558. Its totient is φ = 121905556.

The previous prime is 121905551. The next prime is 121905601. The reversal of 121905557 is 755509121.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 81468676 + 40436881 = 9026^2 + 6359^2 .

It is a cyclic number.

It is not a de Polignac number, because 121905557 - 2¹⁰ = 121904533 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (121905551) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 60952778 + 60952779.

It is an arithmetic number, because the mean of its divisors is an integer number (60952779).

Almost surely, 2^121905557 is an apocalyptic number.

It is an amenable number.

121905557 is a deficient number, since it is larger than the sum of its proper divisors (1).

121905557 is an equidigital number, since it uses as much as digits as its factorization.

121905557 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 15750, while the sum is 35.

The square root of 121905557 is about 11041.0849557460. The cubic root of 121905557 is about 495.8395533873.

The spelling of 121905557 in words is "one hundred twenty-one million, nine hundred five thousand, five hundred fifty-seven".