66606618 has 24 divisors (see below), whose sum is σ = 144250848. Its totient is φ = 20494032.

The previous prime is 66606611. The next prime is 66606667. The reversal of 66606618 is 81660666.

It is a super-2 number, since 2×66606618² = 8872883122795848, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (39).

It is not an unprimeable number, because it can be changed into a prime (66606611) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 31830 + ... + 33857.

It is an arithmetic number, because the mean of its divisors is an integer number (6010452).

Almost surely, 2^66606618 is an apocalyptic number.

66606618 is an abundant number, since it is smaller than the sum of its proper divisors (77644230).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

66606618 is a wasteful number, since it uses less digits than its factorization.

66606618 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 65718 (or 65705 counting only the distinct ones).

The product of its (nonzero) digits is 62208, while the sum is 39.

The square root of 66606618 is about 8161.2877660330. The cubic root of 66606618 is about 405.3583537607.

The spelling of 66606618 in words is "sixty-six million, six hundred six thousand, six hundred eighteen".