66688440000 has 1120 divisors, whose sum is σ = 281545076736. Its totient is φ = 13547520000.

The previous prime is 66688439999. The next prime is 66688440053. The reversal of 66688440000 is 4488666.

66688440000 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a tau number, because it is divible by the number of its divisors (1120).

It is a hoax number, since the sum of its digits (42) 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 (42).

It is a zygodrome in base 10.

It is an unprimeable number.

It is a polite number, since it can be written in 159 ways as a sum of consecutive naturals, for example, 338519902 + ... + 338520098.

Almost surely, 2^66688440000 is an apocalyptic number.

66688440000 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 66688440000, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (140772538368).

66688440000 is an abundant number, since it is smaller than the sum of its proper divisors (214856636736).

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

66688440000 is a wasteful number, since it uses less digits than its factorization.

66688440000 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 283 (or 258 counting only the distinct ones).

The product of its (nonzero) digits is 221184, while the sum is 42.

The spelling of 66688440000 in words is "sixty-six billion, six hundred eighty-eight million, four hundred forty thousand".