81802723 has 2 divisors, whose sum is σ = 81802724. Its totient is φ = 81802722.

The previous prime is 81802709. The next prime is 81802729. The reversal of 81802723 is 32720818.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-81802723 is a prime.

It is not a weakly prime, because it can be changed into another prime (81802729) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 40901361 + 40901362.

It is an arithmetic number, because the mean of its divisors is an integer number (40901362).

Almost surely, 2^81802723 is an apocalyptic number.

81802723 is a deficient number, since it is larger than the sum of its proper divisors (1).

81802723 is an equidigital number, since it uses as much as digits as its factorization.

81802723 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 5376, while the sum is 31.

The square root of 81802723 is about 9044.4857786388. The cubic root of 81802723 is about 434.0994678821.

The spelling of 81802723 in words is "eighty-one million, eight hundred two thousand, seven hundred twenty-three".