81827479 has 2 divisors, whose sum is σ = 81827480. Its totient is φ = 81827478.

The previous prime is 81827441. The next prime is 81827483. The reversal of 81827479 is 97472818.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 81827479 - 2⁷ = 81827351 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (81827279) 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, 40913739 + 40913740.

It is an arithmetic number, because the mean of its divisors is an integer number (40913740).

Almost surely, 2^81827479 is an apocalyptic number.

81827479 is a deficient number, since it is larger than the sum of its proper divisors (1).

81827479 is an equidigital number, since it uses as much as digits as its factorization.

81827479 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 225792, while the sum is 46.

The square root of 81827479 is about 9045.8542437959. The cubic root of 81827479 is about 434.1432540469.

The spelling of 81827479 in words is "eighty-one million, eight hundred twenty-seven thousand, four hundred seventy-nine".