644747446 has 8 divisors (see below), whose sum is σ = 1105281360. Its totient is φ = 276320328.

The previous prime is 644747443. The next prime is 644747471.

644747446 is nontrivially palindromic in base 10.

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

It is a junction number, because it is equal to n+sod(n) for n = 644747396 and 644747405.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (644747443) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 23026681 + ... + 23026708.

It is an arithmetic number, because the mean of its divisors is an integer number (138160170).

Almost surely, 2^644747446 is an apocalyptic number.

644747446 is a deficient number, since it is larger than the sum of its proper divisors (460533914).

644747446 is a wasteful number, since it uses less digits than its factorization.

644747446 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 46053398.

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

The square root of 644747446 is about 25391.8775595662. The cubic root of 644747446 is about 863.8994751516.

The spelling of 644747446 in words is "six hundred forty-four million, seven hundred forty-seven thousand, four hundred forty-six".