644980101 has 8 divisors (see below), whose sum is σ = 862739904. Its totient is φ = 428603520.

The previous prime is 644980087. The next prime is 644980121. The reversal of 644980101 is 101089446.

644980101 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

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

It is not a de Polignac number, because 644980101 - 2⁹ = 644979589 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (644980121) 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, 344716 + ... + 346581.

It is an arithmetic number, because the mean of its divisors is an integer number (107842488).

Almost surely, 2^644980101 is an apocalyptic number.

It is an amenable number.

644980101 is a deficient number, since it is larger than the sum of its proper divisors (217759803).

644980101 is a wasteful number, since it uses less digits than its factorization.

644980101 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 691611.

The product of its (nonzero) digits is 6912, while the sum is 33.

The square root of 644980101 is about 25396.4584341990. The cubic root of 644980101 is about 864.0033744188.

The spelling of 644980101 in words is "six hundred forty-four million, nine hundred eighty thousand, one hundred one".