81542033 has 2 divisors, whose sum is σ = 81542034. Its totient is φ = 81542032.

The previous prime is 81542011. The next prime is 81542063. The reversal of 81542033 is 33024518.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 81504784 + 37249 = 9028^2 + 193^2 .

It is a cyclic number.

It is not a de Polignac number, because 81542033 - 2⁸ = 81541777 is a prime.

It is a Sophie Germain prime.

It is a Chen prime.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 81541993 and 81542011.

It is not a weakly prime, because it can be changed into another prime (81542063) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 40771016 + 40771017.

It is an arithmetic number, because the mean of its divisors is an integer number (40771017).

Almost surely, 2^81542033 is an apocalyptic number.

It is an amenable number.

81542033 is a deficient number, since it is larger than the sum of its proper divisors (1).

81542033 is an equidigital number, since it uses as much as digits as its factorization.

81542033 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 2880, while the sum is 26.

The square root of 81542033 is about 9030.0627351088. The cubic root of 81542033 is about 433.6378458573.

The spelling of 81542033 in words is "eighty-one million, five hundred forty-two thousand, thirty-three".