66660061 has 8 divisors (see below), whose sum is σ = 73143000. Its totient is φ = 60370752.

The previous prime is 66660059. The next prime is 66660071. The reversal of 66660061 is 16006666.

It can be written as a sum of positive squares in 4 ways, for example, as 17799961 + 48860100 = 4219^2 + 6990^2 .

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

It is not a de Polignac number, because 66660061 - 2¹ = 66660059 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 (66660071) 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 7 ways as a sum of consecutive naturals, for example, 47686 + ... + 49063.

It is an arithmetic number, because the mean of its divisors is an integer number (9142875).

Almost surely, 2^66660061 is an apocalyptic number.

It is an amenable number.

66660061 is a deficient number, since it is larger than the sum of its proper divisors (6482939).

66660061 is a wasteful number, since it uses less digits than its factorization.

66660061 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 96815.

The product of its (nonzero) digits is 7776, while the sum is 31.

The square root of 66660061 is about 8164.5612864379. The cubic root of 66660061 is about 405.4667402629.

The spelling of 66660061 in words is "sixty-six million, six hundred sixty thousand, sixty-one".