81851827 has 2 divisors, whose sum is σ = 81851828. Its totient is φ = 81851826.

The previous prime is 81851789. The next prime is 81851831. The reversal of 81851827 is 72815818.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-81851827 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 81851827.

It is not a weakly prime, because it can be changed into another prime (81851857) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 40925913 + 40925914.

It is an arithmetic number, because the mean of its divisors is an integer number (40925914).

Almost surely, 2^81851827 is an apocalyptic number.

81851827 is a deficient number, since it is larger than the sum of its proper divisors (1).

81851827 is an equidigital number, since it uses as much as digits as its factorization.

81851827 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 35840, while the sum is 40.

The square root of 81851827 is about 9047.1999535768. The cubic root of 81851827 is about 434.1863099650.

The spelling of 81851827 in words is "eighty-one million, eight hundred fifty-one thousand, eight hundred twenty-seven".