81033971 has 2 divisors, whose sum is σ = 81033972. Its totient is φ = 81033970.

The previous prime is 81033949. The next prime is 81033977. The reversal of 81033971 is 17933018.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 81033971 - 2¹⁰ = 81032947 is a prime.

It is not a weakly prime, because it can be changed into another prime (81033977) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 40516985 + 40516986.

It is an arithmetic number, because the mean of its divisors is an integer number (40516986).

Almost surely, 2^81033971 is an apocalyptic number.

81033971 is a deficient number, since it is larger than the sum of its proper divisors (1).

81033971 is an equidigital number, since it uses as much as digits as its factorization.

81033971 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 4536, while the sum is 32.

The square root of 81033971 is about 9001.8870799405. The cubic root of 81033971 is about 432.7353498729.

Adding to 81033971 its reverse (17933018), we get a palindrome (98966989).

The spelling of 81033971 in words is "eighty-one million, thirty-three thousand, nine hundred seventy-one".