20316308561 has 16 divisors (see below), whose sum is σ = 21173757696. Its totient is φ = 19477920000.

The previous prime is 20316308557. The next prime is 20316308611. The reversal of 20316308561 is 16580361302.

It is a cyclic number.

It is not a de Polignac number, because 20316308561 - 2² = 20316308557 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20316308161) 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, 894101 + ... + 916541.

It is an arithmetic number, because the mean of its divisors is an integer number (1323359856).

Almost surely, 2^20316308561 is an apocalyptic number.

It is an amenable number.

20316308561 is a deficient number, since it is larger than the sum of its proper divisors (857449135).

20316308561 is a wasteful number, since it uses less digits than its factorization.

20316308561 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 22864.

The product of its (nonzero) digits is 25920, while the sum is 35.

Adding to 20316308561 its reverse (16580361302), we get a palindrome (36896669863).

The spelling of 20316308561 in words is "twenty billion, three hundred sixteen million, three hundred eight thousand, five hundred sixty-one".