644203336 has 32 divisors (see below), whose sum is σ = 1381544640. Its totient is φ = 275865408.

The previous prime is 644203333. The next prime is 644203381. The reversal of 644203336 is 633302446.

It is a super-2 number, since 2×644203336² = 829995876227057792, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 644203298 and 644203307.

It is not an unprimeable number, because it can be changed into a prime (644203331) 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 7 ways as a sum of consecutive naturals, for example, 79170 + ... + 86926.

It is an arithmetic number, because the mean of its divisors is an integer number (43173270).

Almost surely, 2^644203336 is an apocalyptic number.

It is an amenable number.

644203336 is an abundant number, since it is smaller than the sum of its proper divisors (737341304).

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

644203336 is a wasteful number, since it uses less digits than its factorization.

644203336 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9253 (or 9249 counting only the distinct ones).

The product of its (nonzero) digits is 31104, while the sum is 31.

The square root of 644203336 is about 25381.1610451532. The cubic root of 644203336 is about 863.6563884272.

The spelling of 644203336 in words is "six hundred forty-four million, two hundred three thousand, three hundred thirty-six".