81253771 has 2 divisors, whose sum is σ = 81253772. Its totient is φ = 81253770.

The previous prime is 81253729. The next prime is 81253787. The reversal of 81253771 is 17735218.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 81253771 - 2⁷ = 81253643 is a prime.

It is not a weakly prime, because it can be changed into another prime (81256771) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 40626885 + 40626886.

It is an arithmetic number, because the mean of its divisors is an integer number (40626886).

Almost surely, 2^81253771 is an apocalyptic number.

81253771 is a deficient number, since it is larger than the sum of its proper divisors (1).

81253771 is an equidigital number, since it uses as much as digits as its factorization.

81253771 is an evil number, because the sum of its binary digits is even.

The product of its digits is 11760, while the sum is 34.

The square root of 81253771 is about 9014.0873636769. The cubic root of 81253771 is about 433.1262532594.

Adding to 81253771 its reverse (17735218), we get a palindrome (98988989).

The spelling of 81253771 in words is "eighty-one million, two hundred fifty-three thousand, seven hundred seventy-one".