66731947766 has 32 divisors (see below), whose sum is σ = 111880441728. Its totient is φ = 29589315840.

The previous prime is 66731947757. The next prime is 66731947769. The reversal of 66731947766 is 66774913766.

It is a Smith number, since the sum of its digits (62) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a junction number, because it is equal to n+sod(n) for n = 66731947699 and 66731947708.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66731947769) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 699686 + ... + 789318.

It is an arithmetic number, because the mean of its divisors is an integer number (3496263804).

Almost surely, 2^66731947766 is an apocalyptic number.

66731947766 is a deficient number, since it is larger than the sum of its proper divisors (45148493962).

66731947766 is a wasteful number, since it uses less digits than its factorization.

66731947766 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 90476.

The product of its digits is 48009024, while the sum is 62.

The spelling of 66731947766 in words is "sixty-six billion, seven hundred thirty-one million, nine hundred forty-seven thousand, seven hundred sixty-six".