644452007 has 8 divisors (see below), whose sum is σ = 677605440. Its totient is φ = 612027360.

The previous prime is 644452001. The next prime is 644452009. The reversal of 644452007 is 700254446.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 644452007 - 2¹⁸ = 644189863 is a prime.

It is a super-3 number, since 3×644452007³ (a number of 27 digits) contains 333 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (644452001) 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, 180383 + ... + 183920.

It is an arithmetic number, because the mean of its divisors is an integer number (84700680).

Almost surely, 2^644452007 is an apocalyptic number.

644452007 is a deficient number, since it is larger than the sum of its proper divisors (33153433).

644452007 is a wasteful number, since it uses less digits than its factorization.

644452007 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 364393.

The product of its (nonzero) digits is 26880, while the sum is 32.

The square root of 644452007 is about 25386.0593042717. The cubic root of 644452007 is about 863.7675017240.

The spelling of 644452007 in words is "six hundred forty-four million, four hundred fifty-two thousand, seven".