66855518 has 4 divisors (see below), whose sum is σ = 100283280. Its totient is φ = 33427758.

The previous prime is 66855511. The next prime is 66855533. The reversal of 66855518 is 81555866.

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

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66855511) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 16713878 + ... + 16713881.

It is an arithmetic number, because the mean of its divisors is an integer number (25070820).

Almost surely, 2^66855518 is an apocalyptic number.

66855518 is a deficient number, since it is larger than the sum of its proper divisors (33427762).

66855518 is a wasteful number, since it uses less digits than its factorization.

66855518 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 33427761.

The product of its digits is 288000, while the sum is 44.

The square root of 66855518 is about 8176.5223658962. The cubic root of 66855518 is about 405.8626493905.

The spelling of 66855518 in words is "sixty-six million, eight hundred fifty-five thousand, five hundred eighteen".