66199842 has 80 divisors (see below), whose sum is σ = 157164480. Its totient is φ = 20785248.

The previous prime is 66199841. The next prime is 66199843. The reversal of 66199842 is 24899166.

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (66199841) and next prime (66199843).

It is not an unprimeable number, because it can be changed into a prime (66199841) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 39 ways as a sum of consecutive naturals, for example, 406053 + ... + 406215.

It is an arithmetic number, because the mean of its divisors is an integer number (1964556).

Almost surely, 2^66199842 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 66199842, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (78582240).

66199842 is an abundant number, since it is smaller than the sum of its proper divisors (90964638).

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

66199842 is a wasteful number, since it uses less digits than its factorization.

66199842 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 309 (or 300 counting only the distinct ones).

The product of its digits is 186624, while the sum is 45.

The square root of 66199842 is about 8136.3285331899. The cubic root of 66199842 is about 404.5314746551.

It can be divided in two parts, 6619 and 9842, that added together give a palindrome (16461).

The spelling of 66199842 in words is "sixty-six million, one hundred ninety-nine thousand, eight hundred forty-two".