20561022317 has 16 divisors (see below), whose sum is σ = 23754772800. Its totient is φ = 17588509440.

The previous prime is 20561022289. The next prime is 20561022319. The reversal of 20561022317 is 71322016502.

It is a happy number.

It is a cyclic number.

It is not a de Polignac number, because 20561022317 - 2⁶ = 20561022253 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 20561022317.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20561022319) 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, 1163534 + ... + 1181072.

It is an arithmetic number, because the mean of its divisors is an integer number (1484673300).

Almost surely, 2^20561022317 is an apocalyptic number.

It is an amenable number.

20561022317 is a deficient number, since it is larger than the sum of its proper divisors (3193750483).

20561022317 is a wasteful number, since it uses less digits than its factorization.

20561022317 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 23836.

The product of its (nonzero) digits is 5040, while the sum is 29.

Adding to 20561022317 its reverse (71322016502), we get a palindrome (91883038819).

The spelling of 20561022317 in words is "twenty billion, five hundred sixty-one million, twenty-two thousand, three hundred seventeen".