66859806 has 32 divisors (see below), whose sum is σ = 145369728. Its totient is φ = 20377440.

The previous prime is 66859799. The next prime is 66859811. The reversal of 66859806 is 60895866.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 4341 + ... + 12351.

It is an arithmetic number, because the mean of its divisors is an integer number (4542804).

Almost surely, 2^66859806 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 66859806, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (72684864).

66859806 is an abundant number, since it is smaller than the sum of its proper divisors (78509922).

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

66859806 is a wasteful number, since it uses less digits than its factorization.

66859806 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8136.

The product of its (nonzero) digits is 622080, while the sum is 48.

The square root of 66859806 is about 8176.7845758587. The cubic root of 66859806 is about 405.8713263199.

The spelling of 66859806 in words is "sixty-six million, eight hundred fifty-nine thousand, eight hundred six".