66684601 has 4 divisors (see below), whose sum is σ = 68984100. Its totient is φ = 64385104.

The previous prime is 66684593. The next prime is 66684643. The reversal of 66684601 is 10648666.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 18020025 + 48664576 = 4245^2 + 6976^2 .

It is not a de Polignac number, because 66684601 - 2³ = 66684593 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (66684001) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1149706 + ... + 1149763.

It is an arithmetic number, because the mean of its divisors is an integer number (17246025).

Almost surely, 2^66684601 is an apocalyptic number.

It is an amenable number.

66684601 is a deficient number, since it is larger than the sum of its proper divisors (2299499).

66684601 is a wasteful number, since it uses less digits than its factorization.

66684601 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2299498.

The product of its (nonzero) digits is 41472, while the sum is 37.

The square root of 66684601 is about 8166.0639845644. The cubic root of 66684601 is about 405.5164898576.

The spelling of 66684601 in words is "sixty-six million, six hundred eighty-four thousand, six hundred one".