66805781530 has 8 divisors (see below), whose sum is σ = 120250406772. Its totient is φ = 26722312608.

The previous prime is 66805781513. The next prime is 66805781543. The reversal of 66805781530 is 3518750866.

It can be written as a sum of positive squares in 2 ways, for example, as 60453532129 + 6352249401 = 245873^2 + 79701^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3340289067 + ... + 3340289086.

Almost surely, 2^66805781530 is an apocalyptic number.

66805781530 is a deficient number, since it is larger than the sum of its proper divisors (53444625242).

66805781530 is a wasteful number, since it uses less digits than its factorization.

66805781530 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6680578160.

The product of its (nonzero) digits is 1209600, while the sum is 49.

The spelling of 66805781530 in words is "sixty-six billion, eight hundred five million, seven hundred eighty-one thousand, five hundred thirty".