66640720330 has 8 divisors (see below), whose sum is σ = 119953296612. Its totient is φ = 26656288128.

The previous prime is 66640720319. The next prime is 66640720331. The reversal of 66640720330 is 3302704666.

It can be written as a sum of positive squares in 2 ways, for example, as 63893178441 + 2747541889 = 252771^2 + 52417^2 .

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

It is a super-2 number, since 2×66640720330² (a number of 22 digits) contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 66640720330.

It is not an unprimeable number, because it can be changed into a prime (66640720331) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3332036007 + ... + 3332036026.

Almost surely, 2^66640720330 is an apocalyptic number.

66640720330 is a deficient number, since it is larger than the sum of its proper divisors (53312576282).

66640720330 is a wasteful number, since it uses less digits than its factorization.

66640720330 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6664072040.

The product of its (nonzero) digits is 108864, while the sum is 37.

The spelling of 66640720330 in words is "sixty-six billion, six hundred forty million, seven hundred twenty thousand, three hundred thirty".