66857238 has 160 divisors (see below), whose sum is σ = 188179200. Its totient is φ = 17309376.

The previous prime is 66857227. The next prime is 66857279. The reversal of 66857238 is 83275866.

It is a junction number, because it is equal to n+sod(n) for n = 66857193 and 66857202.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 79 ways as a sum of consecutive naturals, for example, 624781 + ... + 624887.

It is an arithmetic number, because the mean of its divisors is an integer number (1176120).

Almost surely, 2^66857238 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 66857238, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (94089600).

66857238 is an abundant number, since it is smaller than the sum of its proper divisors (121321962).

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

66857238 is a wasteful number, since it uses less digits than its factorization.

66857238 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 176 (or 167 counting only the distinct ones).

The product of its digits is 483840, while the sum is 45.

The square root of 66857238 is about 8176.6275444097. The cubic root of 66857238 is about 405.8661299198.

The spelling of 66857238 in words is "sixty-six million, eight hundred fifty-seven thousand, two hundred thirty-eight".