20302178261 has 2 divisors, whose sum is σ = 20302178262. Its totient is φ = 20302178260.

The previous prime is 20302178249. The next prime is 20302178291. The reversal of 20302178261 is 16287120302.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 19258500625 + 1043677636 = 138775^2 + 32306^2 .

It is a cyclic number.

It is not a de Polignac number, because 20302178261 - 2²⁶ = 20235069397 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20302178291) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10151089130 + 10151089131.

It is an arithmetic number, because the mean of its divisors is an integer number (10151089131).

Almost surely, 2^20302178261 is an apocalyptic number.

It is an amenable number.

20302178261 is a deficient number, since it is larger than the sum of its proper divisors (1).

20302178261 is an equidigital number, since it uses as much as digits as its factorization.

20302178261 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 8064, while the sum is 32.

Adding to 20302178261 its reverse (16287120302), we get a palindrome (36589298563).

The spelling of 20302178261 in words is "twenty billion, three hundred two million, one hundred seventy-eight thousand, two hundred sixty-one".