644720027446 has 16 divisors (see below), whose sum is σ = 1057653844560. Its totient is φ = 292316381280.

The previous prime is 644720027401. The next prime is 644720027491.

644720027446 is nontrivially palindromic in base 10.

It is an interprime number because it is at equal distance from previous prime (644720027401) and next prime (644720027491).

It is a junction number, because it is equal to n+sod(n) for n = 644720027396 and 644720027405.

It is a congruent number.

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, 36899901 + ... + 36917368.

It is an arithmetic number, because the mean of its divisors is an integer number (66103365285).

Almost surely, 2^644720027446 is an apocalyptic number.

644720027446 is a deficient number, since it is larger than the sum of its proper divisors (412933817114).

644720027446 is a wasteful number, since it uses less digits than its factorization.

644720027446 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 73817679.

The product of its (nonzero) digits is 1806336, while the sum is 46.

The spelling of 644720027446 in words is "six hundred forty-four billion, seven hundred twenty million, twenty-seven thousand, four hundred forty-six".