81602173349 has 2 divisors, whose sum is σ = 81602173350. Its totient is φ = 81602173348.

The previous prime is 81602173339. The next prime is 81602173361. The reversal of 81602173349 is 94337120618.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 44528596324 + 37073577025 = 211018^2 + 192545^2 .

It is a cyclic number.

It is not a de Polignac number, because 81602173349 - 2³⁶ = 12882696613 is a prime.

It is a Sophie Germain prime.

It is a Curzon number.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (81602173339) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 40801086674 + 40801086675.

It is an arithmetic number, because the mean of its divisors is an integer number (40801086675).

Almost surely, 2^81602173349 is an apocalyptic number.

It is an amenable number.

81602173349 is a deficient number, since it is larger than the sum of its proper divisors (1).

81602173349 is an equidigital number, since it uses as much as digits as its factorization.

81602173349 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 217728, while the sum is 44.

The spelling of 81602173349 in words is "eighty-one billion, six hundred two million, one hundred seventy-three thousand, three hundred forty-nine".