81854837 has 2 divisors, whose sum is σ = 81854838. Its totient is φ = 81854836.

The previous prime is 81854833. The next prime is 81854867. The reversal of 81854837 is 73845818.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 76720081 + 5134756 = 8759^2 + 2266^2 .

It is a cyclic number.

It is not a de Polignac number, because 81854837 - 2² = 81854833 is a prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (81854833) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 40927418 + 40927419.

It is an arithmetic number, because the mean of its divisors is an integer number (40927419).

Almost surely, 2^81854837 is an apocalyptic number.

It is an amenable number.

81854837 is a deficient number, since it is larger than the sum of its proper divisors (1).

81854837 is an equidigital number, since it uses as much as digits as its factorization.

81854837 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 215040, while the sum is 44.

The square root of 81854837 is about 9047.3663018582. The cubic root of 81854837 is about 434.1916321218.

It can be divided in two parts, 818 and 54837, that added together give a palindrome (55655).

The spelling of 81854837 in words is "eighty-one million, eight hundred fifty-four thousand, eight hundred thirty-seven".