81787033 has 2 divisors, whose sum is σ = 81787034. Its totient is φ = 81787032.

The previous prime is 81787019. The next prime is 81787049. The reversal of 81787033 is 33078718.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 81486729 + 300304 = 9027^2 + 548^2 .

It is a cyclic number.

It is not a de Polignac number, because 81787033 - 2²⁵ = 48232601 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 81786983 and 81787001.

It is not a weakly prime, because it can be changed into another prime (81787093) 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, 40893516 + 40893517.

It is an arithmetic number, because the mean of its divisors is an integer number (40893517).

Almost surely, 2^81787033 is an apocalyptic number.

It is an amenable number.

81787033 is a deficient number, since it is larger than the sum of its proper divisors (1).

81787033 is an equidigital number, since it uses as much as digits as its factorization.

81787033 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 28224, while the sum is 37.

The square root of 81787033 is about 9043.6183577150. The cubic root of 81787033 is about 434.0717122610.

The spelling of 81787033 in words is "eighty-one million, seven hundred eighty-seven thousand, thirty-three".