20644101 has 6 divisors (see below), whose sum is σ = 29819270. Its totient is φ = 13762728.

The previous prime is 20644093. The next prime is 20644111. The reversal of 20644101 is 10144602.

20644101 is a `hidden beast` number, since 20 + 644 + 1 + 0 + 1 = 666.

It can be written as a sum of positive squares in only one way, i.e., 20520900 + 123201 = 4530^2 + 351^2 .

It is not a de Polignac number, because 20644101 - 2³ = 20644093 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 (20644111) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 1146886 + ... + 1146903.

Almost surely, 2^20644101 is an apocalyptic number.

It is an amenable number.

20644101 is a deficient number, since it is larger than the sum of its proper divisors (9175169).

20644101 is a wasteful number, since it uses less digits than its factorization.

20644101 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2293795 (or 2293792 counting only the distinct ones).

The product of its (nonzero) digits is 192, while the sum is 18.

The square root of 20644101 is about 4543.5779953688. The cubic root of 20644101 is about 274.3249603208.

Adding to 20644101 its reverse (10144602), we get a palindrome (30788703).

The spelling of 20644101 in words is "twenty million, six hundred forty-four thousand, one hundred one".