66971719494 has 24 divisors (see below), whose sum is σ = 148192742880. Its totient is φ = 21848929488.

The previous prime is 66971719483. The next prime is 66971719511. The reversal of 66971719494 is 49491717966.

66971719494 is a `hidden beast` number, since 6 + 6 + 9 + 71 + 71 + 9 + 494 = 666.

It is a super-2 number, since 2×66971719494² (a number of 22 digits) contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 39580549 + ... + 39582240.

It is an arithmetic number, because the mean of its divisors is an integer number (6174697620).

Almost surely, 2^66971719494 is an apocalyptic number.

66971719494 is an abundant number, since it is smaller than the sum of its proper divisors (81221023386).

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

66971719494 is a wasteful number, since it uses less digits than its factorization.

66971719494 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 79162844 (or 79162841 counting only the distinct ones).

The product of its digits is 20575296, while the sum is 63.

The spelling of 66971719494 in words is "sixty-six billion, nine hundred seventy-one million, seven hundred nineteen thousand, four hundred ninety-four".