644245145 has 8 divisors (see below), whose sum is σ = 773256456. Its totient is φ = 515287936.

The previous prime is 644245117. The next prime is 644245153. The reversal of 644245145 is 541542446.

644245145 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in 4 ways, for example, as 8549776 + 635695369 = 2924^2 + 25213^2 .

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 644245145 - 2¹⁶ = 644179609 is a prime.

It is a Duffinian number.

It is a plaindrome in base 16.

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, 20429 + ... + 41301.

It is an arithmetic number, because the mean of its divisors is an integer number (96657057).

Almost surely, 2^644245145 is an apocalyptic number.

It is an amenable number.

644245145 is a deficient number, since it is larger than the sum of its proper divisors (129011311).

644245145 is a wasteful number, since it uses less digits than its factorization.

644245145 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 27051.

The product of its digits is 76800, while the sum is 35.

The square root of 644245145 is about 25381.9846544749. The cubic root of 644245145 is about 863.6750718804.

The spelling of 644245145 in words is "six hundred forty-four million, two hundred forty-five thousand, one hundred forty-five".