66858888438 has 12 divisors (see below), whose sum is σ = 144860924988. Its totient is φ = 22286296140.

The previous prime is 66858888391. The next prime is 66858888461. The reversal of 66858888438 is 83488885866.

66858888438 is a `hidden beast` number, since 6 + 6 + 8 + 588 + 8 + 8 + 4 + 38 = 666.

It is a super-2 number, since 2×66858888438² (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 5 ways as a sum of consecutive naturals, for example, 1857191328 + ... + 1857191363.

It is an arithmetic number, because the mean of its divisors is an integer number (12071743749).

Almost surely, 2^66858888438 is an apocalyptic number.

66858888438 is an abundant number, since it is smaller than the sum of its proper divisors (78002036550).

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

66858888438 is a wasteful number, since it uses less digits than its factorization.

66858888438 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3714382699 (or 3714382696 counting only the distinct ones).

The product of its digits is 566231040, while the sum is 72.

The spelling of 66858888438 in words is "sixty-six billion, eight hundred fifty-eight million, eight hundred eighty-eight thousand, four hundred thirty-eight".