644222631072 has 48 divisors (see below), whose sum is σ = 1691154944640. Its totient is φ = 214731919872.

The previous prime is 644222631047. The next prime is 644222631083. The reversal of 644222631072 is 270136222446.

It is a tau number, because it is divible by the number of its divisors (48).

It is a self number, because there is not a number n which added to its sum of digits gives 644222631072.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 2415268 + ... + 2668700.

It is an arithmetic number, because the mean of its divisors is an integer number (35232394680).

Almost surely, 2^644222631072 is an apocalyptic number.

It is an amenable number.

644222631072 is an abundant number, since it is smaller than the sum of its proper divisors (1046932313568).

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

644222631072 is a wasteful number, since it uses less digits than its factorization.

644222631072 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 279925 (or 279917 counting only the distinct ones).

The product of its (nonzero) digits is 193536, while the sum is 39.

The spelling of 644222631072 in words is "six hundred forty-four billion, two hundred twenty-two million, six hundred thirty-one thousand, seventy-two".