66808181952 has 168 divisors, whose sum is σ = 203144877936. Its totient is φ = 20919435264.

The previous prime is 66808181899. The next prime is 66808181959. The reversal of 66808181952 is 25918180866.

It is a happy number.

66808181952 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is not an unprimeable number, because it can be changed into a prime (66808181959) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 5349988 + ... + 5362460.

It is an arithmetic number, because the mean of its divisors is an integer number (1209195702).

Almost surely, 2^66808181952 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 66808181952, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (101572438968).

66808181952 is an abundant number, since it is smaller than the sum of its proper divisors (136336695984).

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

66808181952 is a wasteful number, since it uses less digits than its factorization.

66808181952 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 13055 (or 13042 counting only the distinct ones).

The product of its (nonzero) digits is 1658880, while the sum is 54.

The spelling of 66808181952 in words is "sixty-six billion, eight hundred eight million, one hundred eighty-one thousand, nine hundred fifty-two".