644432892358 has 16 divisors (see below), whose sum is σ = 997884711936. Its totient is φ = 311805762120.

The previous prime is 644432892353. The next prime is 644432892379. The reversal of 644432892358 is 853298234446.

It is a super-2 number, since 2×644432892358² (a number of 24 digits) contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (644432892353) by changing a digit.

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, 939685 + ... + 1473727.

It is an arithmetic number, because the mean of its divisors is an integer number (62367794496).

Almost surely, 2^644432892358 is an apocalyptic number.

644432892358 is a deficient number, since it is larger than the sum of its proper divisors (353451819578).

644432892358 is a wasteful number, since it uses less digits than its factorization.

644432892358 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 553539.

The product of its digits is 39813120, while the sum is 58.

The spelling of 644432892358 in words is "six hundred forty-four billion, four hundred thirty-two million, eight hundred ninety-two thousand, three hundred fifty-eight".