644456250002 has 16 divisors (see below), whose sum is σ = 1000470942072. Its totient is φ = 311127982080.

The previous prime is 644456249917. The next prime is 644456250071. The reversal of 644456250002 is 200052654446.

It can be written as a sum of positive squares in 4 ways, for example, as 445771210921 + 198685039081 = 667661^2 + 445741^2 .

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 40503503 + ... + 40519410.

Almost surely, 2^644456250002 is an apocalyptic number.

644456250002 is a deficient number, since it is larger than the sum of its proper divisors (356014692070).

644456250002 is a wasteful number, since it uses less digits than its factorization.

644456250002 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 81023053.

The product of its (nonzero) digits is 230400, while the sum is 38.

The spelling of 644456250002 in words is "six hundred forty-four billion, four hundred fifty-six million, two hundred fifty thousand, two".