81025871 has 2 divisors, whose sum is σ = 81025872. Its totient is φ = 81025870.

The previous prime is 81025843. The next prime is 81025891. The reversal of 81025871 is 17852018.

It is a happy number.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-81025871 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (81025811) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 40512935 + 40512936.

It is an arithmetic number, because the mean of its divisors is an integer number (40512936).

Almost surely, 2^81025871 is an apocalyptic number.

81025871 is a deficient number, since it is larger than the sum of its proper divisors (1).

81025871 is an equidigital number, since it uses as much as digits as its factorization.

81025871 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 4480, while the sum is 32.

The square root of 81025871 is about 9001.4371630312. The cubic root of 81025871 is about 432.7209309279.

Adding to 81025871 its reverse (17852018), we get a palindrome (98877889).

The spelling of 81025871 in words is "eighty-one million, twenty-five thousand, eight hundred seventy-one".