644002062 has 32 divisors (see below), whose sum is σ = 1412256384. Its totient is φ = 194157600.

The previous prime is 644002061. The next prime is 644002081. The reversal of 644002062 is 260200446.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (644002061) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 11764 + ... + 37767.

It is an arithmetic number, because the mean of its divisors is an integer number (44133012).

Almost surely, 2^644002062 is an apocalyptic number.

644002062 is an abundant number, since it is smaller than the sum of its proper divisors (768254322).

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

644002062 is a wasteful number, since it uses less digits than its factorization.

644002062 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 49744.

The product of its (nonzero) digits is 2304, while the sum is 24.

The square root of 644002062 is about 25377.1957079580. The cubic root of 644002062 is about 863.5664325218.

The spelling of 644002062 in words is "six hundred forty-four million, two thousand, sixty-two".