20644406197 has 16 divisors (see below), whose sum is σ = 21496527360. Its totient is φ = 19804262400.

The previous prime is 20644406179. The next prime is 20644406203. The reversal of 20644406197 is 79160444602.

It is a cyclic number.

It is not a de Polignac number, because 20644406197 - 2¹¹ = 20644404149 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 (20644406147) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 4680129 + ... + 4684537.

It is an arithmetic number, because the mean of its divisors is an integer number (1343532960).

Almost surely, 2^20644406197 is an apocalyptic number.

It is an amenable number.

20644406197 is a deficient number, since it is larger than the sum of its proper divisors (852121163).

20644406197 is a wasteful number, since it uses less digits than its factorization.

20644406197 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5724.

The product of its (nonzero) digits is 290304, while the sum is 43.

The spelling of 20644406197 in words is "twenty billion, six hundred forty-four million, four hundred six thousand, one hundred ninety-seven".