644005011 has 16 divisors (see below), whose sum is σ = 926382240. Its totient is φ = 395600640.

The previous prime is 644004997. The next prime is 644005093. The reversal of 644005011 is 110500446.

644005011 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is not a de Polignac number, because 644005011 - 2¹⁴ = 643988627 is a prime.

It is a super-2 number, since 2×644005011² = 829484908386220242, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (644000011) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 7681 + ... + 36701.

It is an arithmetic number, because the mean of its divisors is an integer number (57898890).

Almost surely, 2^644005011 is an apocalyptic number.

644005011 is a deficient number, since it is larger than the sum of its proper divisors (282377229).

644005011 is a wasteful number, since it uses less digits than its factorization.

644005011 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 29606.

The product of its (nonzero) digits is 480, while the sum is 21.

The square root of 644005011 is about 25377.2538112381. The cubic root of 644005011 is about 863.5677506612.

Adding to 644005011 its reverse (110500446), we get a palindrome (754505457).

The spelling of 644005011 in words is "six hundred forty-four million, five thousand, eleven".