81633193 has 2 divisors, whose sum is σ = 81633194. Its totient is φ = 81633192.

The previous prime is 81633151. The next prime is 81633257. The reversal of 81633193 is 39133618.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 81577024 + 56169 = 9032^2 + 237^2 .

It is a cyclic number.

It is not a de Polignac number, because 81633193 - 2¹³ = 81625001 is a prime.

It is not a weakly prime, because it can be changed into another prime (81633143) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 40816596 + 40816597.

It is an arithmetic number, because the mean of its divisors is an integer number (40816597).

Almost surely, 2^81633193 is an apocalyptic number.

It is an amenable number.

81633193 is a deficient number, since it is larger than the sum of its proper divisors (1).

81633193 is an equidigital number, since it uses as much as digits as its factorization.

81633193 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 11664, while the sum is 34.

The square root of 81633193 is about 9035.1089091388. The cubic root of 81633193 is about 433.7993809686.

The spelling of 81633193 in words is "eighty-one million, six hundred thirty-three thousand, one hundred ninety-three".