81548328361 has 2 divisors, whose sum is σ = 81548328362. Its totient is φ = 81548328360.

The previous prime is 81548328341. The next prime is 81548328373. The reversal of 81548328361 is 16382384518.

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., 69192672025 + 12355656336 = 263045^2 + 111156^2 .

It is a cyclic number.

It is not a de Polignac number, because 81548328361 - 2⁷ = 81548328233 is a prime.

It is not a weakly prime, because it can be changed into another prime (81548328311) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 40774164180 + 40774164181.

It is an arithmetic number, because the mean of its divisors is an integer number (40774164181).

Almost surely, 2^81548328361 is an apocalyptic number.

It is an amenable number.

81548328361 is a deficient number, since it is larger than the sum of its proper divisors (1).

81548328361 is an equidigital number, since it uses as much as digits as its factorization.

81548328361 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 1105920, while the sum is 49.

The spelling of 81548328361 in words is "eighty-one billion, five hundred forty-eight million, three hundred twenty-eight thousand, three hundred sixty-one".