644544121400365 has 16 divisors (see below), whose sum is σ = 776704403059200. Its totient is φ = 513467743606272.

The previous prime is 644544121400359. The next prime is 644544121400407. The reversal of 644544121400365 is 563004121445446.

It is a cyclic number.

It is not a de Polignac number, because 644544121400365 - 2⁷ = 644544121400237 is a prime.

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, 55876504 + ... + 66417406.

It is an arithmetic number, because the mean of its divisors is an integer number (48544025191200).

Almost surely, 2^{644544121400365} is an apocalyptic number.

It is an amenable number.

644544121400365 is a deficient number, since it is larger than the sum of its proper divisors (132160281658835).

644544121400365 is a wasteful number, since it uses less digits than its factorization.

644544121400365 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10592316.

The product of its (nonzero) digits is 5529600, while the sum is 49.

The spelling of 644544121400365 in words is "six hundred forty-four trillion, five hundred forty-four billion, one hundred twenty-one million, four hundred thousand, three hundred sixty-five".