5205840020861 has 2 divisors, whose sum is σ = 5205840020862. Its totient is φ = 5205840020860.

The previous prime is 5205840020839. The next prime is 5205840020867. The reversal of 5205840020861 is 1680200485025.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 3322855036900 + 1882984983961 = 1822870^2 + 1372219^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-5205840020861 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (5205840020867) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 2602920010430 + 2602920010431.

It is an arithmetic number, because the mean of its divisors is an integer number (2602920010431).

Almost surely, 2^{5205840020861} is an apocalyptic number.

It is an amenable number.

5205840020861 is a deficient number, since it is larger than the sum of its proper divisors (1).

5205840020861 is an equidigital number, since it uses as much as digits as its factorization.

5205840020861 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 153600, while the sum is 41.

The spelling of 5205840020861 in words is "five trillion, two hundred five billion, eight hundred forty million, twenty thousand, eight hundred sixty-one".