644213152 has 48 divisors (see below), whose sum is σ = 1385893152. Its totient is φ = 292337920.

The previous prime is 644213123. The next prime is 644213159. The reversal of 644213152 is 251312446.

It is a self number, because there is not a number n which added to its sum of digits gives 644213152.

It is not an unprimeable number, because it can be changed into a prime (644213159) 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, 289998 + ... + 292210.

It is an arithmetic number, because the mean of its divisors is an integer number (28872774).

Almost surely, 2^644213152 is an apocalyptic number.

It is an amenable number.

644213152 is an abundant number, since it is smaller than the sum of its proper divisors (741680000).

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

644213152 is a wasteful number, since it uses less digits than its factorization.

644213152 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3061 (or 3053 counting only the distinct ones).

The product of its digits is 5760, while the sum is 28.

The square root of 644213152 is about 25381.3544161851. The cubic root of 644213152 is about 863.6607750380.

Adding to 644213152 its reverse (251312446), we get a palindrome (895525598).

The spelling of 644213152 in words is "six hundred forty-four million, two hundred thirteen thousand, one hundred fifty-two".