644222464446 has 32 divisors (see below), whose sum is σ = 1443564839808. Its totient is φ = 189942740640.

The previous prime is 644222464393. The next prime is 644222464463. The reversal of 644222464446 is 644464222446.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 644222464395 and 644222464404.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 131902240 + ... + 131907123.

It is an arithmetic number, because the mean of its divisors is an integer number (45111401244).

Almost surely, 2^644222464446 is an apocalyptic number.

644222464446 is a gapful number since it is divisible by the number (66) formed by its first and last digit.

644222464446 is an abundant number, since it is smaller than the sum of its proper divisors (799342375362).

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

644222464446 is a wasteful number, since it uses less digits than its factorization.

644222464446 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 263809416.

The product of its digits is 7077888, while the sum is 48.

The spelling of 644222464446 in words is "six hundred forty-four billion, two hundred twenty-two million, four hundred sixty-four thousand, four hundred forty-six".