644053574 has 4 divisors (see below), whose sum is σ = 966080364. Its totient is φ = 322026786.

The previous prime is 644053463. The next prime is 644053589. The reversal of 644053574 is 475350446.

It is a happy number.

644053574 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 161013392 + ... + 161013395.

It is an arithmetic number, because the mean of its divisors is an integer number (241520091).

Almost surely, 2^644053574 is an apocalyptic number.

644053574 is a deficient number, since it is larger than the sum of its proper divisors (322026790).

644053574 is a wasteful number, since it uses less digits than its factorization.

644053574 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 322026789.

The product of its (nonzero) digits is 201600, while the sum is 38.

The square root of 644053574 is about 25378.2106146198. The cubic root of 644053574 is about 863.5894566966.

The spelling of 644053574 in words is "six hundred forty-four million, fifty-three thousand, five hundred seventy-four".