66819738 has 16 divisors (see below), whose sum is σ = 139450176. Its totient is φ = 21304800.

The previous prime is 66819737. The next prime is 66819749. The reversal of 66819738 is 83791866.

It is not an unprimeable number, because it can be changed into a prime (66819737) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 241963 + ... + 242238.

It is an arithmetic number, because the mean of its divisors is an integer number (8715636).

Almost surely, 2^66819738 is an apocalyptic number.

66819738 is an abundant number, since it is smaller than the sum of its proper divisors (72630438).

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

66819738 is a wasteful number, since it uses less digits than its factorization.

66819738 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 484229.

The product of its digits is 435456, while the sum is 48.

The square root of 66819738 is about 8174.3341013198. The cubic root of 66819738 is about 405.7902327453.

The spelling of 66819738 in words is "sixty-six million, eight hundred nineteen thousand, seven hundred thirty-eight".