66138127776 has 240 divisors, whose sum is σ = 227030259456. Its totient is φ = 18494313984.

The previous prime is 66138127739. The next prime is 66138127831. The reversal of 66138127776 is 67772183166.

66138127776 is a `hidden beast` number, since 6 + 613 + 8 + 12 + 7 + 7 + 7 + 6 = 666.

It is a hoax number, since the sum of its digits (54) coincides with the sum of the digits of its distinct prime factors.

It is a Harshad number since it is a multiple of its sum of digits (54).

It is a nude number because it is divisible by every one of its digits.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 39 ways as a sum of consecutive naturals, for example, 813990 + ... + 891546.

Almost surely, 2^66138127776 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 66138127776, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (113515129728).

66138127776 is an abundant number, since it is smaller than the sum of its proper divisors (160892131680).

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

66138127776 is a wasteful number, since it uses less digits than its factorization.

66138127776 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 77633 (or 77616 counting only the distinct ones).

The product of its digits is 3556224, while the sum is 54.

The spelling of 66138127776 in words is "sixty-six billion, one hundred thirty-eight million, one hundred twenty-seven thousand, seven hundred seventy-six".