644536982 has 8 divisors (see below), whose sum is σ = 970568136. Its totient is φ = 321014272.

The previous prime is 644536979. The next prime is 644536987. The reversal of 644536982 is 289635446.

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

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (644536987) 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, 626468 + ... + 627495.

It is an arithmetic number, because the mean of its divisors is an integer number (121321017).

Almost surely, 2^644536982 is an apocalyptic number.

644536982 is a deficient number, since it is larger than the sum of its proper divisors (326031154).

644536982 is a wasteful number, since it uses less digits than its factorization.

644536982 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1254222.

The product of its digits is 1244160, while the sum is 47.

The square root of 644536982 is about 25387.7329039046. The cubic root of 644536982 is about 863.8054644256.

The spelling of 644536982 in words is "six hundred forty-four million, five hundred thirty-six thousand, nine hundred eighty-two".