66417718 has 4 divisors (see below), whose sum is σ = 99626580. Its totient is φ = 33208858.

The previous prime is 66417713. The next prime is 66417727. The reversal of 66417718 is 81771466.

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

It is a super-2 number, since 2×66417718² = 8822626528655048, which contains 22 as substring.

It is a Smith number, since the sum of its digits (40) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66417713) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 16604428 + ... + 16604431.

It is an arithmetic number, because the mean of its divisors is an integer number (24906645).

Almost surely, 2^66417718 is an apocalyptic number.

66417718 is a deficient number, since it is larger than the sum of its proper divisors (33208862).

66417718 is a wasteful number, since it uses less digits than its factorization.

66417718 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 33208861.

The product of its digits is 56448, while the sum is 40.

The square root of 66417718 is about 8149.7066204864. The cubic root of 66417718 is about 404.9747847940.

The spelling of 66417718 in words is "sixty-six million, four hundred seventeen thousand, seven hundred eighteen".