66425783824 has 15 divisors (see below), whose sum is σ = 128701953613. Its totient is φ = 33212376448.

The previous prime is 66425783821. The next prime is 66425783839. The reversal of 66425783824 is 42838752466.

The square root of 66425783824 is 257732.

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

It can be written as a sum of positive squares in only one way, i.e., 29880579600 + 36545204224 = 172860^2 + 191168^2 .

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (66425783821) by changing a digit.

It is a polite number, since it can be written in 2 ways as a sum of consecutive naturals, for example, 998712 + ... + 1063144.

Almost surely, 2^66425783824 is an apocalyptic number.

66425783824 is the 257732-nd square number.

It is an amenable number.

66425783824 is a deficient number, since it is larger than the sum of its proper divisors (62276169789).

66425783824 is an frugal number, since it uses more digits than its factorization.

66425783824 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 128874 (or 64435 counting only the distinct ones).

The product of its digits is 15482880, while the sum is 55.

The spelling of 66425783824 in words is "sixty-six billion, four hundred twenty-five million, seven hundred eighty-three thousand, eight hundred twenty-four".