66251767680 has 384 divisors, whose sum is σ = 261985351680. Its totient is φ = 15112728576.

The previous prime is 66251767661. The next prime is 66251767691. The reversal of 66251767680 is 8676715266.

66251767680 is a `hidden beast` number, since 6 + 6 + 2 + 517 + 67 + 68 + 0 = 666.

It is a tau number, because it is divible by the number of its divisors (384).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 24472887 + ... + 24475593.

It is an arithmetic number, because the mean of its divisors is an integer number (682253520).

Almost surely, 2^66251767680 is an apocalyptic number.

66251767680 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 66251767680, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (130992675840).

66251767680 is an abundant number, since it is smaller than the sum of its proper divisors (195733584000).

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

66251767680 is a wasteful number, since it uses less digits than its factorization.

66251767680 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3346 (or 3331 counting only the distinct ones).

The product of its (nonzero) digits is 5080320, while the sum is 54.

The spelling of 66251767680 in words is "sixty-six billion, two hundred fifty-one million, seven hundred sixty-seven thousand, six hundred eighty".