66659520400 has 240 divisors, whose sum is σ = 179031809088. Its totient is φ = 23645440000.

The previous prime is 66659520377. The next prime is 66659520439. The reversal of 66659520400 is 402595666.

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 47 ways as a sum of consecutive naturals, for example, 45939675 + ... + 45941125.

Almost surely, 2^66659520400 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 66659520400, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (89515904544).

66659520400 is an abundant number, since it is smaller than the sum of its proper divisors (112372288688).

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

66659520400 is a wasteful number, since it uses less digits than its factorization.

66659520400 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1730 (or 1719 counting only the distinct ones).

The product of its (nonzero) digits is 388800, while the sum is 43.

The spelling of 66659520400 in words is "sixty-six billion, six hundred fifty-nine million, five hundred twenty thousand, four hundred".