66219444 has 42 divisors (see below), whose sum is σ = 173754210. Its totient is φ = 22072176.

The previous prime is 66219443. The next prime is 66219449. The reversal of 66219444 is 44491266.

It can be written as a sum of positive squares in only one way, i.e., 35283600 + 30935844 = 5940^2 + 5562^2 .

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a nude number because it is divisible by every one of its digits.

It is a junction number, because it is equal to n+sod(n) for n = 66219399 and 66219408.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66219443) by changing a digit.

It is a polite number, since it can be written in 13 ways as a sum of consecutive naturals, for example, 8439 + ... + 14270.

It is an arithmetic number, because the mean of its divisors is an integer number (4137005).

Almost surely, 2^66219444 is an apocalyptic number.

It is an amenable number.

66219444 is an abundant number, since it is smaller than the sum of its proper divisors (107534766).

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

66219444 is a wasteful number, since it uses less digits than its factorization.

66219444 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 22731 (or 22714 counting only the distinct ones).

The product of its digits is 41472, while the sum is 36.

The square root of 66219444 is about 8137.5330414076. The cubic root of 66219444 is about 404.5713984333.

The spelling of 66219444 in words is "sixty-six million, two hundred nineteen thousand, four hundred forty-four".