644104405 has 8 divisors (see below), whose sum is σ = 883343232. Its totient is φ = 441671568.

The previous prime is 644104361. The next prime is 644104411. The reversal of 644104405 is 504401446.

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 644104405 - 2¹³ = 644096213 is a prime.

It is a Duffinian number.

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, 9201457 + ... + 9201526.

It is an arithmetic number, because the mean of its divisors is an integer number (110417904).

Almost surely, 2^644104405 is an apocalyptic number.

It is an amenable number.

644104405 is a deficient number, since it is larger than the sum of its proper divisors (239238827).

644104405 is a wasteful number, since it uses less digits than its factorization.

644104405 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 18402995.

The product of its (nonzero) digits is 7680, while the sum is 28.

The square root of 644104405 is about 25379.2120642072. The cubic root of 644104405 is about 863.6121752833.

The spelling of 644104405 in words is "six hundred forty-four million, one hundred four thousand, four hundred five".