66545618 has 8 divisors (see below), whose sum is σ = 99876348. Its totient is φ = 33253504.

The previous prime is 66545617. The next prime is 66545621. The reversal of 66545618 is 81654566.

It is a happy number.

It can be written as a sum of positive squares in 2 ways, for example, as 66308449 + 237169 = 8143^2 + 487^2 .

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

It is not an unprimeable number, because it can be changed into a prime (66545617) 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, 4871 + ... + 12522.

Almost surely, 2^66545618 is an apocalyptic number.

66545618 is a deficient number, since it is larger than the sum of its proper divisors (33330730).

66545618 is a wasteful number, since it uses less digits than its factorization.

66545618 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 19308.

The product of its digits is 172800, while the sum is 41.

The square root of 66545618 is about 8157.5497546751. The cubic root of 66545618 is about 405.2345702056.

The spelling of 66545618 in words is "sixty-six million, five hundred forty-five thousand, six hundred eighteen".