66781618766 has 8 divisors (see below), whose sum is σ = 104527751184. Its totient is φ = 31939035040.

The previous prime is 66781618747. The next prime is 66781618769.

66781618766 is nontrivially palindromic in base 10.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a junction number, because it is equal to n+sod(n) for n = 66781618699 and 66781618708.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66781618769) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 725887115 + ... + 725887206.

It is an arithmetic number, because the mean of its divisors is an integer number (13065968898).

Almost surely, 2^66781618766 is an apocalyptic number.

66781618766 is a deficient number, since it is larger than the sum of its proper divisors (37746132418).

66781618766 is a wasteful number, since it uses less digits than its factorization.

66781618766 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1451774346.

The product of its digits is 24385536, while the sum is 62.

The spelling of 66781618766 in words is "sixty-six billion, seven hundred eighty-one million, six hundred eighteen thousand, seven hundred sixty-six".