644545446 has 32 divisors (see below), whose sum is σ = 1377023328. Its totient is φ = 200417280.

The previous prime is 644545403. The next prime is 644545453.

644545446 is nontrivially palindromic in base 10.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 644545398 and 644545407.

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, 16435 + ... + 39486.

It is an arithmetic number, because the mean of its divisors is an integer number (43031979).

Almost surely, 2^644545446 is an apocalyptic number.

644545446 is an abundant number, since it is smaller than the sum of its proper divisors (732477882).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

644545446 is a wasteful number, since it uses less digits than its factorization.

644545446 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 56056.

The product of its digits is 921600, while the sum is 42.

The square root of 644545446 is about 25387.8995980369. The cubic root of 644545446 is about 863.8092455468.

The spelling of 644545446 in words is "six hundred forty-four million, five hundred forty-five thousand, four hundred forty-six".