16205409761 has 2 divisors, whose sum is σ = 16205409762. Its totient is φ = 16205409760.

The previous prime is 16205409721. The next prime is 16205409799. The reversal of 16205409761 is 16790450261.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 13539649600 + 2665760161 = 116360^2 + 51631^2 .

It is a cyclic number.

It is not a de Polignac number, because 16205409761 - 2¹⁸ = 16205147617 is a prime.

It is a Sophie Germain prime.

It is a Curzon number.

It is not a weakly prime, because it can be changed into another prime (16205409721) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 8102704880 + 8102704881.

It is an arithmetic number, because the mean of its divisors is an integer number (8102704881).

Almost surely, 2^16205409761 is an apocalyptic number.

It is an amenable number.

16205409761 is a deficient number, since it is larger than the sum of its proper divisors (1).

16205409761 is an equidigital number, since it uses as much as digits as its factorization.

16205409761 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 90720, while the sum is 41.

The spelling of 16205409761 in words is "sixteen billion, two hundred five million, four hundred nine thousand, seven hundred sixty-one".