66440210 has 16 divisors (see below), whose sum is σ = 119823192. Its totient is φ = 26524800.

The previous prime is 66440201. The next prime is 66440237. The reversal of 66440210 is 1204466.

It is a happy number.

It can be written as a sum of positive squares in 4 ways, for example, as 60481729 + 5958481 = 7777^2 + 2441^2 .

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, 731 + ... + 11550.

Almost surely, 2^66440210 is an apocalyptic number.

66440210 is a deficient number, since it is larger than the sum of its proper divisors (53382982).

66440210 is a wasteful number, since it uses less digits than its factorization.

66440210 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 12829.

The product of its (nonzero) digits is 1152, while the sum is 23.

The square root of 66440210 is about 8151.0864306545. The cubic root of 66440210 is about 405.0204938062.

Adding to 66440210 its reverse (1204466), we get a palindrome (67644676).

The spelling of 66440210 in words is "sixty-six million, four hundred forty thousand, two hundred ten".