644123046 has 32 divisors (see below), whose sum is σ = 1474334208. Its totient is φ = 183778560.

The previous prime is 644123041. The next prime is 644123069. The reversal of 644123046 is 640321446.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (644123041) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 20886 + ... + 41526.

It is an arithmetic number, because the mean of its divisors is an integer number (46072944).

Almost surely, 2^644123046 is an apocalyptic number.

644123046 is an abundant number, since it is smaller than the sum of its proper divisors (830211162).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

644123046 is a wasteful number, since it uses less digits than its factorization.

644123046 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 21396.

The product of its (nonzero) digits is 13824, while the sum is 30.

The square root of 644123046 is about 25379.5793109342. The cubic root of 644123046 is about 863.6205064581.

The spelling of 644123046 in words is "six hundred forty-four million, one hundred twenty-three thousand, forty-six".