666644410 has 8 divisors (see below), whose sum is σ = 1199959956. Its totient is φ = 266657760.

The previous prime is 666644401. The next prime is 666644411. The reversal of 666644410 is 14446666.

It is a happy number.

It can be written as a sum of positive squares in 2 ways, for example, as 588693169 + 77951241 = 24263^2 + 8829^2 .

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

It is a nialpdrome in base 10.

It is a self number, because there is not a number n which added to its sum of digits gives 666644410.

It is not an unprimeable number, because it can be changed into a prime (666644411) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 33332211 + ... + 33332230.

Almost surely, 2^666644410 is an apocalyptic number.

666644410 is a deficient number, since it is larger than the sum of its proper divisors (533315546).

666644410 is a wasteful number, since it uses less digits than its factorization.

666644410 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 66664448.

The product of its (nonzero) digits is 82944, while the sum is 37.

The square root of 666644410 is about 25819.4579726221. The cubic root of 666644410 is about 873.5707431335.

It can be divided in two parts, 6666 and 44410, that added together give a square (51076 = 226²).

The spelling of 666644410 in words is "six hundred sixty-six million, six hundred forty-four thousand, four hundred ten".