644046102 has 72 divisors (see below), whose sum is σ = 1627396056. Its totient is φ = 183544704.

The previous prime is 644046031. The next prime is 644046103. The reversal of 644046102 is 201640446.

644046102 is a `hidden beast` number, since 6 + 4 + 40 + 4 + 610 + 2 = 666.

644046102 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (644046103) by changing a digit.

It is a polite number, since it can be written in 35 ways as a sum of consecutive naturals, for example, 495918 + ... + 497214.

It is an arithmetic number, because the mean of its divisors is an integer number (22602723).

Almost surely, 2^644046102 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 644046102, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (813698028).

644046102 is an abundant number, since it is smaller than the sum of its proper divisors (983349954).

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

644046102 is a wasteful number, since it uses less digits than its factorization.

644046102 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1882 (or 1872 counting only the distinct ones).

The product of its (nonzero) digits is 4608, while the sum is 27.

The square root of 644046102 is about 25378.0634012921. The cubic root of 644046102 is about 863.5861170337.

Adding to 644046102 its reverse (201640446), we get a palindrome (845686548).

The spelling of 644046102 in words is "six hundred forty-four million, forty-six thousand, one hundred two".