66441805 has 8 divisors (see below), whose sum is σ = 79777944. Its totient is φ = 53121600.

The previous prime is 66441769. The next prime is 66441811. The reversal of 66441805 is 50814466.

It can be written as a sum of positive squares in 4 ways, for example, as 1510441 + 64931364 = 1229^2 + 8058^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 66441805 - 2²³ = 58053197 is a prime.

It is a Duffinian number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 9115 + ... + 14695.

It is an arithmetic number, because the mean of its divisors is an integer number (9972243).

Almost surely, 2^66441805 is an apocalyptic number.

It is an amenable number.

66441805 is a deficient number, since it is larger than the sum of its proper divisors (13336139).

66441805 is a wasteful number, since it uses less digits than its factorization.

66441805 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7967.

The product of its (nonzero) digits is 23040, while the sum is 34.

The square root of 66441805 is about 8151.1842697856. The cubic root of 66441805 is about 405.0237348281.

The spelling of 66441805 in words is "sixty-six million, four hundred forty-one thousand, eight hundred five".