81290453 has 2 divisors, whose sum is σ = 81290454. Its totient is φ = 81290452.

The previous prime is 81290437. The next prime is 81290459. The reversal of 81290453 is 35409218.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 71791729 + 9498724 = 8473^2 + 3082^2 .

It is a cyclic number.

It is not a de Polignac number, because 81290453 - 2⁴ = 81290437 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 (81290459) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 40645226 + 40645227.

It is an arithmetic number, because the mean of its divisors is an integer number (40645227).

Almost surely, 2^81290453 is an apocalyptic number.

It is an amenable number.

81290453 is a deficient number, since it is larger than the sum of its proper divisors (1).

81290453 is an equidigital number, since it uses as much as digits as its factorization.

81290453 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 8640, while the sum is 32.

The square root of 81290453 is about 9016.1218381297. The cubic root of 81290453 is about 433.1914217095.

The spelling of 81290453 in words is "eighty-one million, two hundred ninety thousand, four hundred fifty-three".