644047534 has 16 divisors (see below), whose sum is σ = 1040869872. Its totient is φ = 297114048.

The previous prime is 644047531. The next prime is 644047543. The reversal of 644047534 is 435740446.

644047534 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a junction number, because it is equal to n+sod(n) for n = 644047493 and 644047502.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (644047531) 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, 69562 + ... + 78274.

It is an arithmetic number, because the mean of its divisors is an integer number (65054367).

Almost surely, 2^644047534 is an apocalyptic number.

644047534 is a deficient number, since it is larger than the sum of its proper divisors (396822338).

644047534 is a wasteful number, since it uses less digits than its factorization.

644047534 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 11571.

The product of its (nonzero) digits is 161280, while the sum is 37.

The square root of 644047534 is about 25378.0916146191. The cubic root of 644047534 is about 863.5867570782.

The spelling of 644047534 in words is "six hundred forty-four million, forty-seven thousand, five hundred thirty-four".