16209573581 has 2 divisors, whose sum is σ = 16209573582. Its totient is φ = 16209573580.

The previous prime is 16209573553. The next prime is 16209573599. The reversal of 16209573581 is 18537590261.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 16087117225 + 122456356 = 126835^2 + 11066^2 .

It is a cyclic number.

It is not a de Polignac number, because 16209573581 - 2²² = 16205379277 is a prime.

It is a super-2 number, since 2×16209573581² (a number of 21 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (16209573181) 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, 8104786790 + 8104786791.

It is an arithmetic number, because the mean of its divisors is an integer number (8104786791).

Almost surely, 2^16209573581 is an apocalyptic number.

It is an amenable number.

16209573581 is a deficient number, since it is larger than the sum of its proper divisors (1).

16209573581 is an equidigital number, since it uses as much as digits as its factorization.

16209573581 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 453600, while the sum is 47.

The spelling of 16209573581 in words is "sixteen billion, two hundred nine million, five hundred seventy-three thousand, five hundred eighty-one".