66817668 has 24 divisors (see below), whose sum is σ = 162687168. Its totient is φ = 21304096.

The previous prime is 66817649. The next prime is 66817669. The reversal of 66817668 is 86671866.

It is a super-3 number, since 3×66817668³ (a number of 24 digits) contains 333 as substring.

It is not an unprimeable number, because it can be changed into a prime (66817669) 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, 120771 + ... + 121322.

It is an arithmetic number, because the mean of its divisors is an integer number (6778632).

Almost surely, 2^66817668 is an apocalyptic number.

It is an amenable number.

66817668 is an abundant number, since it is smaller than the sum of its proper divisors (95869500).

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

66817668 is a wasteful number, since it uses less digits than its factorization.

66817668 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 242123 (or 242121 counting only the distinct ones).

The product of its digits is 580608, while the sum is 48.

The square root of 66817668 is about 8174.2074845211. The cubic root of 66817668 is about 405.7860423944.

It can be divided in two parts, 668 and 17668, that added together give a triangular number (18336 = T₁₉₁).

The spelling of 66817668 in words is "sixty-six million, eight hundred seventeen thousand, six hundred sixty-eight".