66305661 has 8 divisors (see below), whose sum is σ = 93608064. Its totient is φ = 41603520.

The previous prime is 66305639. The next prime is 66305677. The reversal of 66305661 is 16650366.

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

It is not a de Polignac number, because 66305661 - 2¹¹ = 66303613 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66315661) 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, 650005 + ... + 650106.

It is an arithmetic number, because the mean of its divisors is an integer number (11701008).

Almost surely, 2^66305661 is an apocalyptic number.

It is an amenable number.

66305661 is a deficient number, since it is larger than the sum of its proper divisors (27302403).

66305661 is a wasteful number, since it uses less digits than its factorization.

66305661 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1300131.

The product of its (nonzero) digits is 19440, while the sum is 33.

The square root of 66305661 is about 8142.8288082214. The cubic root of 66305661 is about 404.7469048148.

It can be divided in two parts, 66305 and 661, that added together give a palindrome (66966).

The spelling of 66305661 in words is "sixty-six million, three hundred five thousand, six hundred sixty-one".