66333561 has 16 divisors (see below), whose sum is σ = 101382144. Its totient is φ = 37791504.

The previous prime is 66333559. The next prime is 66333571. The reversal of 66333561 is 16533366.

It is not a de Polignac number, because 66333561 - 2¹ = 66333559 is a prime.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (66333511) 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, 2736 + ... + 11838.

It is an arithmetic number, because the mean of its divisors is an integer number (6336384).

Almost surely, 2^66333561 is an apocalyptic number.

It is an amenable number.

66333561 is a deficient number, since it is larger than the sum of its proper divisors (35048583).

66333561 is a wasteful number, since it uses less digits than its factorization.

66333561 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9460.

The product of its digits is 29160, while the sum is 33.

The square root of 66333561 is about 8144.5417918997. The cubic root of 66333561 is about 404.8036664597.

The spelling of 66333561 in words is "sixty-six million, three hundred thirty-three thousand, five hundred sixty-one".