66194878878 has 12 divisors (see below), whose sum is σ = 143422237608. Its totient is φ = 22064959620.

The previous prime is 66194878877. The next prime is 66194878879. The reversal of 66194878878 is 87887849166.

66194878878 is a `hidden beast` number, since 6 + 61 + 9 + 487 + 8 + 87 + 8 = 666.

It is an interprime number because it is at equal distance from previous prime (66194878877) and next prime (66194878879).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66194878873) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 1838746618 + ... + 1838746653.

It is an arithmetic number, because the mean of its divisors is an integer number (11951853134).

Almost surely, 2^66194878878 is an apocalyptic number.

66194878878 is an abundant number, since it is smaller than the sum of its proper divisors (77227358730).

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

66194878878 is a wasteful number, since it uses less digits than its factorization.

66194878878 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3677493279 (or 3677493276 counting only the distinct ones).

The product of its digits is 260112384, while the sum is 72.

The spelling of 66194878878 in words is "sixty-six billion, one hundred ninety-four million, eight hundred seventy-eight thousand, eight hundred seventy-eight".