20602516861 has 2 divisors, whose sum is σ = 20602516862. Its totient is φ = 20602516860.

The previous prime is 20602516853. The next prime is 20602516871. The reversal of 20602516861 is 16861520602.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 20601147961 + 1368900 = 143531^2 + 1170^2 .

It is a cyclic number.

It is not a de Polignac number, because 20602516861 - 2³ = 20602516853 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 20602516861.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20602516841) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10301258430 + 10301258431.

It is an arithmetic number, because the mean of its divisors is an integer number (10301258431).

Almost surely, 2^20602516861 is an apocalyptic number.

It is an amenable number.

20602516861 is a deficient number, since it is larger than the sum of its proper divisors (1).

20602516861 is an equidigital number, since it uses as much as digits as its factorization.

20602516861 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 34560, while the sum is 37.

The spelling of 20602516861 in words is "twenty billion, six hundred two million, five hundred sixteen thousand, eight hundred sixty-one".