81659033 has 2 divisors, whose sum is σ = 81659034. Its totient is φ = 81659032.

The previous prime is 81659029. The next prime is 81659051. The reversal of 81659033 is 33095618.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 64128064 + 17530969 = 8008^2 + 4187^2 .

It is a cyclic number.

It is not a de Polignac number, because 81659033 - 2² = 81659029 is a prime.

It is a Chen prime.

It is a junction number, because it is equal to n+sod(n) for n = 81658984 and 81659002.

It is not a weakly prime, because it can be changed into another prime (81659023) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 40829516 + 40829517.

It is an arithmetic number, because the mean of its divisors is an integer number (40829517).

Almost surely, 2^81659033 is an apocalyptic number.

It is an amenable number.

81659033 is a deficient number, since it is larger than the sum of its proper divisors (1).

81659033 is an equidigital number, since it uses as much as digits as its factorization.

81659033 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 19440, while the sum is 35.

The square root of 81659033 is about 9036.5387732251. The cubic root of 81659033 is about 433.8451474560.

The spelling of 81659033 in words is "eighty-one million, six hundred fifty-nine thousand, thirty-three".