644783038 has 16 divisors (see below), whose sum is σ = 1024791264. Its totient is φ = 303212800.

The previous prime is 644783011. The next prime is 644783059. The reversal of 644783038 is 830387446.

It is a happy number.

It is a junction number, because it is equal to n+sod(n) for n = 644782985 and 644783003.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 48738 + ... + 60538.

It is an arithmetic number, because the mean of its divisors is an integer number (64049454).

Almost surely, 2^644783038 is an apocalyptic number.

644783038 is a deficient number, since it is larger than the sum of its proper divisors (380008226).

644783038 is a wasteful number, since it uses less digits than its factorization.

644783038 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 13427.

The product of its (nonzero) digits is 387072, while the sum is 43.

The square root of 644783038 is about 25392.5784039353. The cubic root of 644783038 is about 863.9153714763.

The spelling of 644783038 in words is "six hundred forty-four million, seven hundred eighty-three thousand, thirty-eight".