66697576394 has 4 divisors (see below), whose sum is σ = 100046364594. Its totient is φ = 33348788196.

The previous prime is 66697576373. The next prime is 66697576397. The reversal of 66697576394 is 49367579666.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 49367579666 = 2 ⋅24683789833.

It can be written as a sum of positive squares in only one way, i.e., 66622320769 + 75255625 = 258113^2 + 8675^2 .

It is not an unprimeable number, because it can be changed into a prime (66697576397) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 16674394097 + ... + 16674394100.

Almost surely, 2^66697576394 is an apocalyptic number.

66697576394 is a deficient number, since it is larger than the sum of its proper divisors (33348788200).

66697576394 is a wasteful number, since it uses less digits than its factorization.

66697576394 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 33348788199.

The product of its digits is 308629440, while the sum is 68.

The spelling of 66697576394 in words is "sixty-six billion, six hundred ninety-seven million, five hundred seventy-six thousand, three hundred ninety-four".