644510851962 has 16 divisors (see below), whose sum is σ = 1289051923680. Its totient is φ = 214831914032.

The previous prime is 644510851951. The next prime is 644510851967. The reversal of 644510851962 is 269158015446.

It is not an unprimeable number, because it can be changed into a prime (644510851967) 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, 977037 + ... + 1497872.

It is an arithmetic number, because the mean of its divisors is an integer number (80565745230).

Almost surely, 2^644510851962 is an apocalyptic number.

644510851962 is an abundant number, since it is smaller than the sum of its proper divisors (644541071718).

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

644510851962 is a wasteful number, since it uses less digits than its factorization.

644510851962 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2518317.

The product of its (nonzero) digits is 2073600, while the sum is 51.

The spelling of 644510851962 in words is "six hundred forty-four billion, five hundred ten million, eight hundred fifty-one thousand, nine hundred sixty-two".