66687897600 has 351 divisors, whose sum is σ = 239752969963. Its totient is φ = 17717329920.

The previous prime is 66687897587. The next prime is 66687897611. The reversal of 66687897600 is 679878666.

The square root of 66687897600 is 258240.

It is a perfect power (a square), and thus also a powerful number.

It can be written as a sum of positive squares in 4 ways, for example, as 25579524096 + 41108373504 = 159936^2 + 202752^2 .

It is a Duffinian number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 26 ways as a sum of consecutive naturals, for example, 247910266 + ... + 247910534.

Almost surely, 2^66687897600 is an apocalyptic number.

66687897600 is a gapful number since it is divisible by the number (60) formed by its first and last digit.

66687897600 is the 258240-th square number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 66687897600

66687897600 is an abundant number, since it is smaller than the sum of its proper divisors (173065072363).

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

66687897600 is an equidigital number, since it uses as much as digits as its factorization.

66687897600 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 578 (or 279 counting only the distinct ones).

The product of its (nonzero) digits is 36578304, while the sum is 63.

The spelling of 66687897600 in words is "sixty-six billion, six hundred eighty-seven million, eight hundred ninety-seven thousand, six hundred".