66949255808 has 64 divisors (see below), whose sum is σ = 135704227200. Its totient is φ = 32892659712.

The previous prime is 66949255801. The next prime is 66949255811. The reversal of 66949255808 is 80855294966.

It is a tau number, because it is divible by the number of its divisors (64).

It is not an unprimeable number, because it can be changed into a prime (66949255801) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 3498041 + ... + 3517127.

It is an arithmetic number, because the mean of its divisors is an integer number (2120378550).

Almost surely, 2^66949255808 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 66949255808, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (67852113600).

66949255808 is an abundant number, since it is smaller than the sum of its proper divisors (68754971392).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

66949255808 is a wasteful number, since it uses less digits than its factorization.

66949255808 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 19577 (or 19565 counting only the distinct ones).

The product of its (nonzero) digits is 37324800, while the sum is 62.

The spelling of 66949255808 in words is "sixty-six billion, nine hundred forty-nine million, two hundred fifty-five thousand, eight hundred eight".