20261312647 has 2 divisors, whose sum is σ = 20261312648. Its totient is φ = 20261312646.

The previous prime is 20261312633. The next prime is 20261312681. The reversal of 20261312647 is 74621316202.

It is an a-pointer prime, because the next prime (20261312681) can be obtained adding 20261312647 to its sum of digits (34).

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 20261312647 - 2¹¹ = 20261310599 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20261312047) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10130656323 + 10130656324.

It is an arithmetic number, because the mean of its divisors is an integer number (10130656324).

Almost surely, 2^20261312647 is an apocalyptic number.

20261312647 is a deficient number, since it is larger than the sum of its proper divisors (1).

20261312647 is an equidigital number, since it uses as much as digits as its factorization.

20261312647 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 24192, while the sum is 34.

Adding to 20261312647 its reverse (74621316202), we get a palindrome (94882628849).

The spelling of 20261312647 in words is "twenty billion, two hundred sixty-one million, three hundred twelve thousand, six hundred forty-seven".