644000424506 has 8 divisors (see below), whose sum is σ = 967734930420. Its totient is φ = 321422114368.

The previous prime is 644000424467. The next prime is 644000424559. The reversal of 644000424506 is 605424000446.

644000424506 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in 2 ways, for example, as 616656825625 + 27343598881 = 785275^2 + 165359^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a Curzon number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 289047551 + ... + 289049778.

Almost surely, 2^644000424506 is an apocalyptic number.

644000424506 is a deficient number, since it is larger than the sum of its proper divisors (323734505914).

644000424506 is a wasteful number, since it uses less digits than its factorization.

644000424506 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 578097888.

The product of its (nonzero) digits is 92160, while the sum is 35.

The spelling of 644000424506 in words is "six hundred forty-four billion, four hundred twenty-four thousand, five hundred six".