66631605 has 8 divisors (see below), whose sum is σ = 106610592. Its totient is φ = 35536848.

The previous prime is 66631603. The next prime is 66631633. The reversal of 66631605 is 50613666.

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

It is not a de Polignac number, because 66631605 - 2¹ = 66631603 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66631603) 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, 2221039 + ... + 2221068.

It is an arithmetic number, because the mean of its divisors is an integer number (13326324).

Almost surely, 2^66631605 is an apocalyptic number.

It is an amenable number.

66631605 is a deficient number, since it is larger than the sum of its proper divisors (39978987).

66631605 is a wasteful number, since it uses less digits than its factorization.

66631605 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4442115.

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

The square root of 66631605 is about 8162.8184470806. The cubic root of 66631605 is about 405.4090365266.

The spelling of 66631605 in words is "sixty-six million, six hundred thirty-one thousand, six hundred five".