644100113 has 8 divisors (see below), whose sum is σ = 670765056. Its totient is φ = 617803200.

The previous prime is 644100103. The next prime is 644100137. The reversal of 644100113 is 311001446.

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 644100113 - 2⁶ = 644100049 is a prime.

It is a super-2 number, since 2×644100113² = 829729911133225538, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (644100103) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 88433 + ... + 95438.

It is an arithmetic number, because the mean of its divisors is an integer number (83845632).

Almost surely, 2^644100113 is an apocalyptic number.

It is an amenable number.

644100113 is a deficient number, since it is larger than the sum of its proper divisors (26664943).

644100113 is a wasteful number, since it uses less digits than its factorization.

644100113 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 184015.

The product of its (nonzero) digits is 288, while the sum is 20.

The square root of 644100113 is about 25379.1275066737. The cubic root of 644100113 is about 863.6102570478.

Adding to 644100113 its reverse (311001446), we get a palindrome (955101559).

The spelling of 644100113 in words is "six hundred forty-four million, one hundred thousand, one hundred thirteen".