66105961 has 2 divisors, whose sum is σ = 66105962. Its totient is φ = 66105960.

The previous prime is 66105947. The next prime is 66105967. The reversal of 66105961 is 16950166.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 58982400 + 7123561 = 7680^2 + 2669^2 .

It is a cyclic number.

It is not a de Polignac number, because 66105961 - 2⁷ = 66105833 is a prime.

It is not a weakly prime, because it can be changed into another prime (66105967) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 33052980 + 33052981.

It is an arithmetic number, because the mean of its divisors is an integer number (33052981).

Almost surely, 2^66105961 is an apocalyptic number.

It is an amenable number.

66105961 is a deficient number, since it is larger than the sum of its proper divisors (1).

66105961 is an equidigital number, since it uses as much as digits as its factorization.

66105961 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 9720, while the sum is 34.

The square root of 66105961 is about 8130.5572379758. The cubic root of 66105961 is about 404.3401560403.

The spelling of 66105961 in words is "sixty-six million, one hundred five thousand, nine hundred sixty-one".