644102022 has 8 divisors (see below), whose sum is σ = 1288204056. Its totient is φ = 214700672.

The previous prime is 644102003. The next prime is 644102023. The reversal of 644102022 is 220201446.

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

644102022 is an admirable number.

It is a self number, because there is not a number n which added to its sum of digits gives 644102022.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (644102023) 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, 53675163 + ... + 53675174.

It is an arithmetic number, because the mean of its divisors is an integer number (161025507).

Almost surely, 2^644102022 is an apocalyptic number.

644102022 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.

644102022 is a wasteful number, since it uses less digits than its factorization.

644102022 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 107350342.

The product of its (nonzero) digits is 768, while the sum is 21.

The square root of 644102022 is about 25379.1651162917. The cubic root of 644102022 is about 863.6111102435.

Adding to 644102022 its reverse (220201446), we get a palindrome (864303468).

The spelling of 644102022 in words is "six hundred forty-four million, one hundred two thousand, twenty-two".