66609018 has 48 divisors (see below), whose sum is σ = 170267136. Its totient is φ = 18416160.

The previous prime is 66609017. The next prime is 66609029. The reversal of 66609018 is 81090666.

It is a super-2 number, since 2×66609018² = 8873522557848648, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (66609017) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 4621 + ... + 12432.

It is an arithmetic number, because the mean of its divisors is an integer number (3547232).

Almost surely, 2^66609018 is an apocalyptic number.

66609018 is an abundant number, since it is smaller than the sum of its proper divisors (103658118).

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

66609018 is a wasteful number, since it uses less digits than its factorization.

66609018 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 17099 (or 17096 counting only the distinct ones).

The product of its (nonzero) digits is 15552, while the sum is 36.

The square root of 66609018 is about 8161.4348003277. The cubic root of 66609018 is about 405.3632223879.

The spelling of 66609018 in words is "sixty-six million, six hundred nine thousand, eighteen".