644060101 has 4 divisors (see below), whose sum is σ = 666269100. Its totient is φ = 621851104.

The previous prime is 644060089. The next prime is 644060141. The reversal of 644060101 is 101060446.

644060101 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 101060446 = 2 ⋅50530223.

It can be written as a sum of positive squares in 2 ways, for example, as 307300900 + 336759201 = 17530^2 + 18351^2 .

It is a cyclic number.

It is not a de Polignac number, because 644060101 - 2¹⁵ = 644027333 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (644060141) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 11104456 + ... + 11104513.

It is an arithmetic number, because the mean of its divisors is an integer number (166567275).

Almost surely, 2^644060101 is an apocalyptic number.

It is an amenable number.

644060101 is a deficient number, since it is larger than the sum of its proper divisors (22208999).

644060101 is a wasteful number, since it uses less digits than its factorization.

644060101 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 22208998.

The product of its (nonzero) digits is 576, while the sum is 22.

The square root of 644060101 is about 25378.3392088608. The cubic root of 644060101 is about 863.5923739639.

The spelling of 644060101 in words is "six hundred forty-four million, sixty thousand, one hundred one".