66561041 has 2 divisors, whose sum is σ = 66561042. Its totient is φ = 66561040.

The previous prime is 66561037. The next prime is 66561059. The reversal of 66561041 is 14016566.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 65286400 + 1274641 = 8080^2 + 1129^2 .

It is a cyclic number.

It is not a de Polignac number, because 66561041 - 2² = 66561037 is a prime.

It is a Chen prime.

It is a junction number, because it is equal to n+sod(n) for n = 66560995 and 66561013.

It is not a weakly prime, because it can be changed into another prime (66561031) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 33280520 + 33280521.

It is an arithmetic number, because the mean of its divisors is an integer number (33280521).

Almost surely, 2^66561041 is an apocalyptic number.

It is an amenable number.

66561041 is a deficient number, since it is larger than the sum of its proper divisors (1).

66561041 is an equidigital number, since it uses as much as digits as its factorization.

66561041 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 4320, while the sum is 29.

The square root of 66561041 is about 8158.4950205292. The cubic root of 66561041 is about 405.2658742954.

The spelling of 66561041 in words is "sixty-six million, five hundred sixty-one thousand, forty-one".