81280373 has 2 divisors, whose sum is σ = 81280374. Its totient is φ = 81280372.

The previous prime is 81280361. The next prime is 81280421. The reversal of 81280373 is 37308218.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 48539089 + 32741284 = 6967^2 + 5722^2 .

It is a cyclic number.

It is not a de Polignac number, because 81280373 - 2⁸ = 81280117 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (81280333) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 40640186 + 40640187.

It is an arithmetic number, because the mean of its divisors is an integer number (40640187).

Almost surely, 2^81280373 is an apocalyptic number.

It is an amenable number.

81280373 is a deficient number, since it is larger than the sum of its proper divisors (1).

81280373 is an equidigital number, since it uses as much as digits as its factorization.

81280373 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 8064, while the sum is 32.

The square root of 81280373 is about 9015.5628221426. The cubic root of 81280373 is about 433.1735157527.

The spelling of 81280373 in words is "eighty-one million, two hundred eighty thousand, three hundred seventy-three".