644054514330540 has 48 divisors (see below), whose sum is σ = 1808187365765088. Its totient is φ = 171287420427264.

The previous prime is 644054514330529. The next prime is 644054514330541. The reversal of 644054514330540 is 45033415450446.

It is a self number, because there is not a number n which added to its sum of digits gives 644054514330540.

It is not an unprimeable number, because it can be changed into a prime (644054514330541) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 14389041837 + ... + 14389086596.

It is an arithmetic number, because the mean of its divisors is an integer number (37670570120106).

Almost surely, 2^{644054514330540} is an apocalyptic number.

644054514330540 is a gapful number since it is divisible by the number (60) formed by its first and last digit.

It is an amenable number.

644054514330540 is an abundant number, since it is smaller than the sum of its proper divisors (1164132851434548).

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

644054514330540 is a wasteful number, since it uses less digits than its factorization.

644054514330540 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 28778128818 (or 28778128816 counting only the distinct ones).

The product of its (nonzero) digits is 6912000, while the sum is 48.

Adding to 644054514330540 its reverse (45033415450446), we get a palindrome (689087929780986).

The spelling of 644054514330540 in words is "six hundred forty-four trillion, fifty-four billion, five hundred fourteen million, three hundred thirty thousand, five hundred forty".