81371453 has 2 divisors, whose sum is σ = 81371454. Its totient is φ = 81371452.

The previous prime is 81371371. The next prime is 81371461. The reversal of 81371453 is 35417318.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 80766169 + 605284 = 8987^2 + 778^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-81371453 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 (81371753) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 40685726 + 40685727.

It is an arithmetic number, because the mean of its divisors is an integer number (40685727).

Almost surely, 2^81371453 is an apocalyptic number.

It is an amenable number.

81371453 is a deficient number, since it is larger than the sum of its proper divisors (1).

81371453 is an equidigital number, since it uses as much as digits as its factorization.

81371453 is an evil number, because the sum of its binary digits is even.

The product of its digits is 10080, while the sum is 32.

The square root of 81371453 is about 9020.6126732057. The cubic root of 81371453 is about 433.3352551526.

The spelling of 81371453 in words is "eighty-one million, three hundred seventy-one thousand, four hundred fifty-three".