66543361600 has 63 divisors (see below), whose sum is σ = 163763652787. Its totient is φ = 26613217280.

The previous prime is 66543361561. The next prime is 66543361609. The reversal of 66543361600 is 616334566.

The square root of 66543361600 is 257960.

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 13591829056 + 52951532544 = 116584^2 + 230112^2 .

It is a super-3 number, since 3×66543361600³ (a number of 33 digits) contains 333 as substring.

It is a Harshad number since it is a multiple of its sum of digits (40).

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (66543361609) by changing a digit.

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 8 ways as a sum of consecutive naturals, for example, 10315176 + ... + 10321624.

Almost surely, 2^66543361600 is an apocalyptic number.

66543361600 is the 257960-th square number.

It is an amenable number.

66543361600 is an abundant number, since it is smaller than the sum of its proper divisors (97220291187).

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

66543361600 is an frugal number, since it uses more digits than its factorization.

66543361600 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 12920 (or 6456 counting only the distinct ones).

The product of its (nonzero) digits is 233280, while the sum is 40.

The spelling of 66543361600 in words is "sixty-six billion, five hundred forty-three million, three hundred sixty-one thousand, six hundred".