121551056161 has 2 divisors, whose sum is σ = 121551056162. Its totient is φ = 121551056160.

The previous prime is 121551056113. The next prime is 121551056183. The reversal of 121551056161 is 161650155121.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 121404161761 + 146894400 = 348431^2 + 12120^2 .

It is a cyclic number.

It is not a de Polignac number, because 121551056161 - 2¹⁹ = 121550531873 is a prime.

It is not a weakly prime, because it can be changed into another prime (121551053161) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 60775528080 + 60775528081.

It is an arithmetic number, because the mean of its divisors is an integer number (60775528081).

Almost surely, 2^121551056161 is an apocalyptic number.

It is an amenable number.

121551056161 is a deficient number, since it is larger than the sum of its proper divisors (1).

121551056161 is an equidigital number, since it uses as much as digits as its factorization.

121551056161 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 9000, while the sum is 34.

The spelling of 121551056161 in words is "one hundred twenty-one billion, five hundred fifty-one million, fifty-six thousand, one hundred sixty-one".