644469000 has 128 divisors (see below), whose sum is σ = 2298067200. Its totient is φ = 147302400.

The previous prime is 644468983. The next prime is 644469019. The reversal of 644469000 is 964446.

It is a super-2 number, since 2×644469000² = 830680583922000000, which contains 22 as substring.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 5656 + ... + 36344.

It is an arithmetic number, because the mean of its divisors is an integer number (17953650).

Almost surely, 2^644469000 is an apocalyptic number.

644469000 is a gapful number since it is divisible by the number (60) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 644469000, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1149033600).

644469000 is an abundant number, since it is smaller than the sum of its proper divisors (1653598200).

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

644469000 is a wasteful number, since it uses less digits than its factorization.

644469000 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 30720 (or 30706 counting only the distinct ones).

The product of its (nonzero) digits is 20736, while the sum is 33.

The square root of 644469000 is about 25386.3939936337. The cubic root of 644469000 is about 863.7750936377.

The spelling of 644469000 in words is "six hundred forty-four million, four hundred sixty-nine thousand".