644437034 has 4 divisors (see below), whose sum is σ = 966655554. Its totient is φ = 322218516.

The previous prime is 644437033. The next prime is 644437091. The reversal of 644437034 is 430734446.

It is a happy number.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in only one way, i.e., 644398225 + 38809 = 25385^2 + 197^2 .

It is a junction number, because it is equal to n+sod(n) for n = 644436985 and 644437003.

It is not an unprimeable number, because it can be changed into a prime (644437033) 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 as a sum of consecutive naturals, namely, 161109257 + ... + 161109260.

Almost surely, 2^644437034 is an apocalyptic number.

644437034 is a deficient number, since it is larger than the sum of its proper divisors (322218520).

644437034 is a wasteful number, since it uses less digits than its factorization.

644437034 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 322218519.

The product of its (nonzero) digits is 96768, while the sum is 35.

The square root of 644437034 is about 25385.7643966062. The cubic root of 644437034 is about 863.7608121692.

The spelling of 644437034 in words is "six hundred forty-four million, four hundred thirty-seven thousand, thirty-four".