644505446 has 16 divisors (see below), whose sum is σ = 1050680400. Its totient is φ = 294733728.

The previous prime is 644505427. The next prime is 644505481.

644505446 is nontrivially palindromic in base 10.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 110876 + ... + 116543.

It is an arithmetic number, because the mean of its divisors is an integer number (65667525).

Almost surely, 2^644505446 is an apocalyptic number.

644505446 is a deficient number, since it is larger than the sum of its proper divisors (406174954).

644505446 is a wasteful number, since it uses less digits than its factorization.

644505446 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 227543.

The product of its (nonzero) digits is 230400, while the sum is 38.

The square root of 644505446 is about 25387.1118089475. Note that the first 3 decimals coincide. The cubic root of 644505446 is about 863.7913760623.

It can be divided in two parts, 64450 and 5446, that added together give a palindrome (69896).

The spelling of 644505446 in words is "six hundred forty-four million, five hundred five thousand, four hundred forty-six".