6645166406 has 4 divisors (see below), whose sum is σ = 9967749612. Its totient is φ = 3322583202.

The previous prime is 6645166309. The next prime is 6645166453. The reversal of 6645166406 is 6046615466.

It is a semiprime because it is the product of two primes.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1661291600 + ... + 1661291603.

It is an arithmetic number, because the mean of its divisors is an integer number (2491937403).

Almost surely, 2^6645166406 is an apocalyptic number.

6645166406 is a deficient number, since it is larger than the sum of its proper divisors (3322583206).

6645166406 is a wasteful number, since it uses less digits than its factorization.

6645166406 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3322583205.

The product of its (nonzero) digits is 622080, while the sum is 44.

The square root of 6645166406 is about 81517.8900978184. The cubic root of 6645166406 is about 1880.0466268427.

The spelling of 6645166406 in words is "six billion, six hundred forty-five million, one hundred sixty-six thousand, four hundred six".