66878442 has 48 divisors (see below), whose sum is σ = 161516160. Its totient is φ = 19875456.

The previous prime is 66878429. The next prime is 66878443. The reversal of 66878442 is 24487866.

It is not an unprimeable number, because it can be changed into a prime (66878443) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 63 + ... + 11565.

It is an arithmetic number, because the mean of its divisors is an integer number (3364920).

Almost surely, 2^66878442 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 66878442, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (80758080).

66878442 is an abundant number, since it is smaller than the sum of its proper divisors (94637718).

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

66878442 is a wasteful number, since it uses less digits than its factorization.

66878442 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 11547 (or 11544 counting only the distinct ones).

The product of its digits is 516096, while the sum is 45.

The square root of 66878442 is about 8177.9240642109. The cubic root of 66878442 is about 405.9090326582.

It can be divided in two parts, 6687 and 8442, that added together give a square (15129 = 123²).

The spelling of 66878442 in words is "sixty-six million, eight hundred seventy-eight thousand, four hundred forty-two".