644622045 has 8 divisors (see below), whose sum is σ = 1031395296. Its totient is φ = 343798416.

The previous prime is 644622019. The next prime is 644622059. The reversal of 644622045 is 540226446.

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

It is not a de Polignac number, because 644622045 - 2⁷ = 644621917 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 644621997 and 644622015.

It is a congruent number.

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, 21487387 + ... + 21487416.

It is an arithmetic number, because the mean of its divisors is an integer number (128924412).

Almost surely, 2^644622045 is an apocalyptic number.

It is an amenable number.

644622045 is a deficient number, since it is larger than the sum of its proper divisors (386773251).

644622045 is a wasteful number, since it uses less digits than its factorization.

644622045 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 42974811.

The product of its (nonzero) digits is 46080, while the sum is 33.

The square root of 644622045 is about 25389.4081262246. The cubic root of 644622045 is about 863.8434630996.

The spelling of 644622045 in words is "six hundred forty-four million, six hundred twenty-two thousand, forty-five".