644450132 has 24 divisors (see below), whose sum is σ = 1203417600. Its totient is φ = 301081536.

The previous prime is 644450129. The next prime is 644450137. The reversal of 644450132 is 231054446.

It is a junction number, because it is equal to n+sod(n) for n = 644450095 and 644450104.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (644450137) 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, 52532 + ... + 63627.

It is an arithmetic number, because the mean of its divisors is an integer number (50142400).

Almost surely, 2^644450132 is an apocalyptic number.

It is an amenable number.

644450132 is a deficient number, since it is larger than the sum of its proper divisors (558967468).

644450132 is a wasteful number, since it uses less digits than its factorization.

644450132 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 116255 (or 116253 counting only the distinct ones).

The product of its (nonzero) digits is 11520, while the sum is 29.

The square root of 644450132 is about 25386.0223745273. The cubic root of 644450132 is about 863.7666640275.

The spelling of 644450132 in words is "six hundred forty-four million, four hundred fifty thousand, one hundred thirty-two".