66333661 has 4 divisors (see below), whose sum is σ = 66425632. Its totient is φ = 66241692.

The previous prime is 66333647. The next prime is 66333671. The reversal of 66333661 is 16633366.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 66333661 - 2¹⁵ = 66300893 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66333601) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 44895 + ... + 46348.

It is an arithmetic number, because the mean of its divisors is an integer number (16606408).

Almost surely, 2^66333661 is an apocalyptic number.

It is an amenable number.

66333661 is a deficient number, since it is larger than the sum of its proper divisors (91971).

66333661 is an equidigital number, since it uses as much as digits as its factorization.

66333661 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 91970.

The product of its digits is 34992, while the sum is 34.

The square root of 66333661 is about 8144.5479309781. The cubic root of 66333661 is about 404.8038698778.

The spelling of 66333661 in words is "sixty-six million, three hundred thirty-three thousand, six hundred sixty-one".