644435173475105 has 8 divisors (see below), whose sum is σ = 773350899839592. Its totient is φ = 515529011000448.

The previous prime is 644435173475099. The next prime is 644435173475111. The reversal of 644435173475105 is 501574371534446.

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (644435173475099) and next prime (644435173475111).

It can be written as a sum of positive squares in 4 ways, for example, as 73690841729569 + 570744331745536 = 8584337^2 + 23890256^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 644435173475105 - 2⁴ = 644435173475089 is a prime.

It is a super-2 number, since 2×644435173475105² (a number of 30 digits) contains 22 as substring.

It is a Duffinian 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, 2390824214 + ... + 2391093743.

It is an arithmetic number, because the mean of its divisors is an integer number (96668862479949).

Almost surely, 2^{644435173475105} is an apocalyptic number.

It is an amenable number.

644435173475105 is a deficient number, since it is larger than the sum of its proper divisors (128915726364487).

644435173475105 is a wasteful number, since it uses less digits than its factorization.

644435173475105 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4781944915.

The product of its (nonzero) digits is 84672000, while the sum is 59.

The spelling of 644435173475105 in words is "six hundred forty-four trillion, four hundred thirty-five billion, one hundred seventy-three million, four hundred seventy-five thousand, one hundred five".