644123121321446 has 32 divisors (see below), whose sum is σ = 1052202840534720. Its totient is φ = 293945838759936.

The previous prime is 644123121321409. The next prime is 644123121321517.

644123121321446 is nontrivially palindromic in base 10.

It is a junction number, because it is equal to n+sod(n) for n = 644123121321397 and 644123121321406.

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, 574253510 + ... + 575374086.

It is an arithmetic number, because the mean of its divisors is an integer number (32881338766710).

Almost surely, 2^{644123121321446} is an apocalyptic number.

644123121321446 is a deficient number, since it is larger than the sum of its proper divisors (408079719213274).

644123121321446 is a wasteful number, since it uses less digits than its factorization.

644123121321446 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1369088.

The product of its digits is 663552, while the sum is 44.

The spelling of 644123121321446 in words is "six hundred forty-four trillion, one hundred twenty-three billion, one hundred twenty-one million, three hundred twenty-one thousand, four hundred forty-six".