120166561 has 2 divisors, whose sum is σ = 120166562. Its totient is φ = 120166560.

The previous prime is 120166547. The next prime is 120166567. The reversal of 120166561 is 165661021.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 70040161 + 50126400 = 8369^2 + 7080^2 .

It is a cyclic number.

It is not a de Polignac number, because 120166561 - 2¹⁹ = 119642273 is a prime.

It is not a weakly prime, because it can be changed into another prime (120166567) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 60083280 + 60083281.

It is an arithmetic number, because the mean of its divisors is an integer number (60083281).

Almost surely, 2^120166561 is an apocalyptic number.

It is an amenable number.

120166561 is a deficient number, since it is larger than the sum of its proper divisors (1).

120166561 is an equidigital number, since it uses as much as digits as its factorization.

120166561 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 2160, while the sum is 28.

The square root of 120166561 is about 10962.0509486136. The cubic root of 120166561 is about 493.4705175565.

The spelling of 120166561 in words is "one hundred twenty million, one hundred sixty-six thousand, five hundred sixty-one".