81240584273 has 2 divisors, whose sum is σ = 81240584274. Its totient is φ = 81240584272.

The previous prime is 81240584219. The next prime is 81240584287. The reversal of 81240584273 is 37248504218.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 51721220929 + 29519363344 = 227423^2 + 171812^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-81240584273 is a prime.

It is not a weakly prime, because it can be changed into another prime (81240584203) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 40620292136 + 40620292137.

It is an arithmetic number, because the mean of its divisors is an integer number (40620292137).

Almost surely, 2^81240584273 is an apocalyptic number.

It is an amenable number.

81240584273 is a deficient number, since it is larger than the sum of its proper divisors (1).

81240584273 is an equidigital number, since it uses as much as digits as its factorization.

81240584273 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 430080, while the sum is 44.

The spelling of 81240584273 in words is "eighty-one billion, two hundred forty million, five hundred eighty-four thousand, two hundred seventy-three".