66594561 has 16 divisors (see below), whose sum is σ = 99484608. Its totient is φ = 39268800.

The previous prime is 66594557. The next prime is 66594581. The reversal of 66594561 is 16549566.

It is not a de Polignac number, because 66594561 - 2² = 66594557 is a prime.

It is not an unprimeable number, because it can be changed into a prime (66594511) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 26050 + ... + 28491.

It is an arithmetic number, because the mean of its divisors is an integer number (6217788).

Almost surely, 2^66594561 is an apocalyptic number.

It is an amenable number.

66594561 is a deficient number, since it is larger than the sum of its proper divisors (32890047).

66594561 is a wasteful number, since it uses less digits than its factorization.

66594561 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 54592.

The product of its digits is 194400, while the sum is 42.

The square root of 66594561 is about 8160.5490624100. The cubic root of 66594561 is about 405.3338932254. Note that the first 3 decimals are identical.

The spelling of 66594561 in words is "sixty-six million, five hundred ninety-four thousand, five hundred sixty-one".