20516394401 has 2 divisors, whose sum is σ = 20516394402. Its totient is φ = 20516394400.

The previous prime is 20516394361. The next prime is 20516394403. The reversal of 20516394401 is 10449361502.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 12908368225 + 7608026176 = 113615^2 + 87224^2 .

It is a cyclic number.

It is not a de Polignac number, because 20516394401 - 2¹⁴ = 20516378017 is a prime.

Together with 20516394403, it forms a pair of twin primes.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (20516394403) 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, 10258197200 + 10258197201.

It is an arithmetic number, because the mean of its divisors is an integer number (10258197201).

Almost surely, 2^20516394401 is an apocalyptic number.

It is an amenable number.

20516394401 is a deficient number, since it is larger than the sum of its proper divisors (1).

20516394401 is an equidigital number, since it uses as much as digits as its factorization.

20516394401 is an odious number, because the sum of its binary digits is odd.

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

The spelling of 20516394401 in words is "twenty billion, five hundred sixteen million, three hundred ninety-four thousand, four hundred one".