66861008 has 40 divisors (see below), whose sum is σ = 135408000. Its totient is φ = 31941504.

The previous prime is 66860999. The next prime is 66861013. The reversal of 66861008 is 80016866.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 47093 + ... + 48491.

It is an arithmetic number, because the mean of its divisors is an integer number (3385200).

Almost surely, 2^66861008 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 66861008, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (67704000).

66861008 is an abundant number, since it is smaller than the sum of its proper divisors (68546992).

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

66861008 is a wasteful number, since it uses less digits than its factorization.

66861008 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1539 (or 1533 counting only the distinct ones).

The product of its (nonzero) digits is 13824, while the sum is 35.

The square root of 66861008 is about 8176.8580763029. The cubic root of 66861008 is about 405.8737585456.

The spelling of 66861008 in words is "sixty-six million, eight hundred sixty-one thousand, eight".