66518629900800 has 3840 divisors, whose sum is σ = 299865950208000. Its totient is φ = 12839917977600.

The previous prime is 66518629900777. The next prime is 66518629900819. The reversal of 66518629900800 is 800992681566.

It is a tau number, because it is divible by the number of its divisors (3840).

It is a Harshad number since it is a multiple of its sum of digits (60).

It is an unprimeable number.

It is a polite number, since it can be written in 383 ways as a sum of consecutive naturals, for example, 278320627081 + ... + 278320627319.

It is an arithmetic number, because the mean of its divisors is an integer number (78090091200).

Almost surely, 2^{66518629900800} is an apocalyptic number.

66518629900800 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 66518629900800, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (149932975104000).

66518629900800 is an abundant number, since it is smaller than the sum of its proper divisors (233347320307200).

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

66518629900800 is a wasteful number, since it uses less digits than its factorization.

66518629900800 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 432 (or 397 counting only the distinct ones).

The product of its (nonzero) digits is 11197440, while the sum is 60.

The spelling of 66518629900800 in words is "sixty-six trillion, five hundred eighteen billion, six hundred twenty-nine million, nine hundred thousand, eight hundred".