66071808 has 216 divisors, whose sum is σ = 217481600. Its totient is φ = 19768320.

The previous prime is 66071791. The next prime is 66071821. The reversal of 66071808 is 80817066.

It is a tau number, because it is divible by the number of its divisors (216).

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 836313 + ... + 836391.

Almost surely, 2^66071808 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 66071808, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (108740800).

66071808 is an abundant number, since it is smaller than the sum of its proper divisors (151409792).

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

66071808 is a wasteful number, since it uses less digits than its factorization.

66071808 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 126 (or 95 counting only the distinct ones).

The product of its (nonzero) digits is 16128, while the sum is 36.

The square root of 66071808 is about 8128.4566800839. The cubic root of 66071808 is about 404.2705112458.

The spelling of 66071808 in words is "sixty-six million, seventy-one thousand, eight hundred eight".