181962516809 has 2 divisors, whose sum is σ = 181962516810. Its totient is φ = 181962516808.

The previous prime is 181962516793. The next prime is 181962516823. The reversal of 181962516809 is 908615269181.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 149921516809 + 32041000000 = 387197^2 + 179000^2 .

It is an emirp because it is prime and its reverse (908615269181) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 181962516809 - 2⁴ = 181962516793 is a prime.

It is a super-2 number, since 2×181962516809² (a number of 23 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (181962516839) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 90981258404 + 90981258405.

It is an arithmetic number, because the mean of its divisors is an integer number (90981258405).

Almost surely, 2^181962516809 is an apocalyptic number.

It is an amenable number.

181962516809 is a deficient number, since it is larger than the sum of its proper divisors (1).

181962516809 is an equidigital number, since it uses as much as digits as its factorization.

181962516809 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 1866240, while the sum is 56.

The spelling of 181962516809 in words is "one hundred eighty-one billion, nine hundred sixty-two million, five hundred sixteen thousand, eight hundred nine".