81838751 has 2 divisors, whose sum is σ = 81838752. Its totient is φ = 81838750.

The previous prime is 81838741. The next prime is 81838763. The reversal of 81838751 is 15783818.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 81838751 - 2¹⁰ = 81837727 is a prime.

It is a Chen prime.

It is a junction number, because it is equal to n+sod(n) for n = 81838699 and 81838708.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (81838741) 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, 40919375 + 40919376.

It is an arithmetic number, because the mean of its divisors is an integer number (40919376).

Almost surely, 2^81838751 is an apocalyptic number.

81838751 is a deficient number, since it is larger than the sum of its proper divisors (1).

81838751 is an equidigital number, since it uses as much as digits as its factorization.

81838751 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 53760, while the sum is 41.

The square root of 81838751 is about 9046.4772701864. The cubic root of 81838751 is about 434.1631880109.

The spelling of 81838751 in words is "eighty-one million, eight hundred thirty-eight thousand, seven hundred fifty-one".