66745808 has 20 divisors (see below), whose sum is σ = 136927620. Its totient is φ = 31409664.

The previous prime is 66745807. The next prime is 66745813. The reversal of 66745808 is 80854766.

It can be written as a sum of positive squares in 2 ways, for example, as 53114944 + 13630864 = 7288^2 + 3692^2 .

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66745807) 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, 122423 + ... + 122966.

It is an arithmetic number, because the mean of its divisors is an integer number (6846381).

Almost surely, 2^66745808 is an apocalyptic number.

66745808 is a gapful number since it is divisible by the number (68) formed by its first and last digit.

It is an amenable number.

66745808 is an abundant number, since it is smaller than the sum of its proper divisors (70181812).

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

66745808 is a wasteful number, since it uses less digits than its factorization.

66745808 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 245414 (or 245408 counting only the distinct ones).

The product of its (nonzero) digits is 322560, while the sum is 44.

The square root of 66745808 is about 8169.8107689224. The cubic root of 66745808 is about 405.6405207803.

The spelling of 66745808 in words is "sixty-six million, seven hundred forty-five thousand, eight hundred eight".