66549552784 has 225 divisors, whose sum is σ = 157419594795. Its totient is φ = 27241843200.

The previous prime is 66549552781. The next prime is 66549552799. The reversal of 66549552784 is 48725594566.

The square root of 66549552784 is 257972.

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 44327091600 + 22222461184 = 210540^2 + 149072^2 .

It is a Duffinian number.

Its product of digits (72576000) is a multiple of the sum of its prime factors (160).

It is not an unprimeable number, because it can be changed into a prime (66549552781) by changing a digit.

It is a polite number, since it can be written in 44 ways as a sum of consecutive naturals, for example, 1623159804 + ... + 1623159844.

Almost surely, 2^66549552784 is an apocalyptic number.

66549552784 is the 257972-nd square number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 66549552784

66549552784 is an abundant number, since it is smaller than the sum of its proper divisors (90870042011).

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

66549552784 is an equidigital number, since it uses as much as digits as its factorization.

66549552784 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 160 (or 67 counting only the distinct ones).

The product of its digits is 72576000, while the sum is 61.

The spelling of 66549552784 in words is "sixty-six billion, five hundred forty-nine million, five hundred fifty-two thousand, seven hundred eighty-four".