644159445 has 16 divisors (see below), whose sum is σ = 1036616832. Its totient is φ = 341564480.

The previous prime is 644159429. The next prime is 644159471. The reversal of 644159445 is 544951446.

It is not a de Polignac number, because 644159445 - 2⁴ = 644159429 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 644159397 and 644159406.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 121521 + ... + 126710.

It is an arithmetic number, because the mean of its divisors is an integer number (64788552).

Almost surely, 2^644159445 is an apocalyptic number.

It is an amenable number.

644159445 is a deficient number, since it is larger than the sum of its proper divisors (392457387).

644159445 is a wasteful number, since it uses less digits than its factorization.

644159445 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 248412.

The product of its digits is 345600, while the sum is 42.

The square root of 644159445 is about 25380.2963930684. The cubic root of 644159445 is about 863.6367737075.

The spelling of 644159445 in words is "six hundred forty-four million, one hundred fifty-nine thousand, four hundred forty-five".