644510252 has 24 divisors (see below), whose sum is σ = 1175683824. Its totient is φ = 308860992.

The previous prime is 644510249. The next prime is 644510287. The reversal of 644510252 is 252015446.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 22583 + ... + 42414.

It is an arithmetic number, because the mean of its divisors is an integer number (48986826).

Almost surely, 2^644510252 is an apocalyptic number.

It is an amenable number.

644510252 is a deficient number, since it is larger than the sum of its proper divisors (531173572).

644510252 is a wasteful number, since it uses less digits than its factorization.

644510252 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 65105 (or 65103 counting only the distinct ones).

The product of its (nonzero) digits is 9600, while the sum is 29.

The square root of 644510252 is about 25387.2064630987. The cubic root of 644510252 is about 863.7935231199.

Adding to 644510252 its reverse (252015446), we get a palindrome (896525698).

The spelling of 644510252 in words is "six hundred forty-four million, five hundred ten thousand, two hundred fifty-two".