66555279975600 has 1440 divisors, whose sum is σ = 268607831331840. Its totient is φ = 15119529984000.

The previous prime is 66555279975563. The next prime is 66555279975649. The reversal of 66555279975600 is 657997255566.

66555279975600 is a `hidden beast` number, since 6 + 6 + 5 + 5 + 5 + 2 + 7 + 9 + 9 + 7 + 5 + 600 = 666.

It is a Harshad number since it is a multiple of its sum of digits (72).

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 287 ways as a sum of consecutive naturals, for example, 44878812459 + ... + 44878813941.

Almost surely, 2^{66555279975600} is an apocalyptic number.

66555279975600 is a gapful number since it is divisible by the number (60) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 66555279975600, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (134303915665920).

66555279975600 is an abundant number, since it is smaller than the sum of its proper divisors (202052551356240).

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

66555279975600 is a wasteful number, since it uses less digits than its factorization.

66555279975600 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2811 (or 2797 counting only the distinct ones).

The product of its (nonzero) digits is 1071630000, while the sum is 72.

The spelling of 66555279975600 in words is "sixty-six trillion, five hundred fifty-five billion, two hundred seventy-nine million, nine hundred seventy-five thousand, six hundred".