644829006 has 16 divisors (see below), whose sum is σ = 1365520464. Its totient is φ = 202299264.

The previous prime is 644829001. The next prime is 644829043. The reversal of 644829006 is 600928446.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (644829001) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 3160825 + ... + 3161028.

It is an arithmetic number, because the mean of its divisors is an integer number (85345029).

Almost surely, 2^644829006 is an apocalyptic number.

644829006 is an abundant number, since it is smaller than the sum of its proper divisors (720691458).

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

644829006 is a wasteful number, since it uses less digits than its factorization.

644829006 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6321875.

The product of its (nonzero) digits is 82944, while the sum is 39.

The square root of 644829006 is about 25393.4835341668. The cubic root of 644829006 is about 863.9359011303.

The spelling of 644829006 in words is "six hundred forty-four million, eight hundred twenty-nine thousand, six".