644684707486446 has 64 divisors (see below), whose sum is σ = 1501469337139200. Its totient is φ = 182470231893600.

The previous prime is 644684707486381. The next prime is 644684707486481.

644684707486446 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 (29) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 3620352076 + ... + 3620530143.

It is an arithmetic number, because the mean of its divisors is an integer number (23460458392800).

Almost surely, 2^{644684707486446} is an apocalyptic number.

644684707486446 is a gapful number since it is divisible by the number (66) formed by its first and last digit.

644684707486446 is an abundant number, since it is smaller than the sum of its proper divisors (856784629652754).

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

644684707486446 is a wasteful number, since it uses less digits than its factorization.

644684707486446 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7240882325.

The product of its (nonzero) digits is 16647192576, while the sum is 78.

The spelling of 644684707486446 in words is "six hundred forty-four trillion, six hundred eighty-four billion, seven hundred seven million, four hundred eighty-six thousand, four hundred forty-six".