644648106 has 8 divisors (see below), whose sum is σ = 1289296224. Its totient is φ = 214882700.

The previous prime is 644648089. The next prime is 644648107. The reversal of 644648106 is 601846446.

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

644648106 is an admirable number.

It is not an unprimeable number, because it can be changed into a prime (644648107) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 53720670 + ... + 53720681.

It is an arithmetic number, because the mean of its divisors is an integer number (161162028).

Almost surely, 2^644648106 is an apocalyptic number.

644648106 is a primitive abundant number, since it is smaller than the sum of its proper divisors, none of which is abundant.

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

644648106 is a wasteful number, since it uses less digits than its factorization.

644648106 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 107441356.

The product of its (nonzero) digits is 110592, while the sum is 39.

The square root of 644648106 is about 25389.9213468652. The cubic root of 644648106 is about 863.8551041955.

The spelling of 644648106 in words is "six hundred forty-four million, six hundred forty-eight thousand, one hundred six".