644728827446 has 32 divisors (see below), whose sum is σ = 1060520947200. Its totient is φ = 291528547200.

The previous prime is 644728827443. The next prime is 644728827487.

644728827446 is nontrivially palindromic in base 10.

644728827446 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 (644728827443) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 28782911 + ... + 28805301.

It is an arithmetic number, because the mean of its divisors is an integer number (33141279600).

Almost surely, 2^644728827446 is an apocalyptic number.

644728827446 is a deficient number, since it is larger than the sum of its proper divisors (415792119754).

644728827446 is a wasteful number, since it uses less digits than its factorization.

644728827446 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 29180.

The product of its digits is 115605504, while the sum is 62.

The spelling of 644728827446 in words is "six hundred forty-four billion, seven hundred twenty-eight million, eight hundred twenty-seven thousand, four hundred forty-six".