644166301102431 has 16 divisors (see below), whose sum is σ = 867398480446080. Its totient is φ = 425189222359200.

The previous prime is 644166301102361. The next prime is 644166301102451. The reversal of 644166301102431 is 134201103661446.

It is not a de Polignac number, because 644166301102431 - 2²¹ = 644166299005279 is a prime.

It is a super-2 number, since 2×644166301102431² (a number of 30 digits) contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (644166301102451) by changing a digit.

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 15 ways as a sum of consecutive naturals, for example, 34985460 + ... + 50122998.

It is an arithmetic number, because the mean of its divisors is an integer number (54212405027880).

Almost surely, 2^{644166301102431} is an apocalyptic number.

644166301102431 is a deficient number, since it is larger than the sum of its proper divisors (223232179343649).

644166301102431 is a wasteful number, since it uses less digits than its factorization.

644166301102431 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 15278086.

The product of its (nonzero) digits is 248832, while the sum is 42.

Adding to 644166301102431 its reverse (134201103661446), we get a palindrome (778367404763877).

The spelling of 644166301102431 in words is "six hundred forty-four trillion, one hundred sixty-six billion, three hundred one million, one hundred two thousand, four hundred thirty-one".