66939493966 has 4 divisors (see below), whose sum is σ = 100409240952. Its totient is φ = 33469746982.

The previous prime is 66939493909. The next prime is 66939493979.

66939493966 is nontrivially palindromic in base 10.

It is a semiprime because it is the product of two primes.

It is a junction number, because it is equal to n+sod(n) for n = 66939493895 and 66939493904.

It is a congruent number.

It is an unprimeable number.

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, 16734873490 + ... + 16734873493.

It is an arithmetic number, because the mean of its divisors is an integer number (25102310238).

Almost surely, 2^66939493966 is an apocalyptic number.

66939493966 is a deficient number, since it is larger than the sum of its proper divisors (33469746986).

66939493966 is a wasteful number, since it uses less digits than its factorization.

66939493966 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 33469746985.

The product of its digits is 306110016, while the sum is 70.

The spelling of 66939493966 in words is "sixty-six billion, nine hundred thirty-nine million, four hundred ninety-three thousand, nine hundred sixty-six".