66440404 has 6 divisors (see below), whose sum is σ = 116270714. Its totient is φ = 33220200.

The previous prime is 66440401. The next prime is 66440447. The reversal of 66440404 is 40404466.

It can be written as a sum of positive squares in only one way, i.e., 39087504 + 27352900 = 6252^2 + 5230^2 .

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66440401) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 8305047 + ... + 8305054.

Almost surely, 2^66440404 is an apocalyptic number.

It is an amenable number.

66440404 is a deficient number, since it is larger than the sum of its proper divisors (49830310).

66440404 is a wasteful number, since it uses less digits than its factorization.

66440404 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 16610105 (or 16610103 counting only the distinct ones).

The product of its (nonzero) digits is 9216, while the sum is 28.

The square root of 66440404 is about 8151.0983309000. The cubic root of 66440404 is about 405.0208880148.

The spelling of 66440404 in words is "sixty-six million, four hundred forty thousand, four hundred four".