66302561 has 8 divisors (see below), whose sum is σ = 72111144. Its totient is φ = 60595200.

The previous prime is 66302539. The next prime is 66302611. The reversal of 66302561 is 16520366.

It can be written as a sum of positive squares in 4 ways, for example, as 4774225 + 61528336 = 2185^2 + 7844^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 66302561 - 2¹⁸ = 66040417 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (66302501) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 23936 + ... + 26561.

It is an arithmetic number, because the mean of its divisors is an integer number (9013893).

Almost surely, 2^66302561 is an apocalyptic number.

It is an amenable number.

66302561 is a deficient number, since it is larger than the sum of its proper divisors (5808583).

66302561 is a wasteful number, since it uses less digits than its factorization.

66302561 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 50611.

The product of its (nonzero) digits is 6480, while the sum is 29.

The square root of 66302561 is about 8142.6384544569. The cubic root of 66302561 is about 404.7405969826.

The spelling of 66302561 in words is "sixty-six million, three hundred two thousand, five hundred sixty-one".