81757927 has 2 divisors, whose sum is σ = 81757928. Its totient is φ = 81757926.

The previous prime is 81757919. The next prime is 81757997. The reversal of 81757927 is 72975718.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 81757927 - 2³ = 81757919 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (81757997) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 40878963 + 40878964.

It is an arithmetic number, because the mean of its divisors is an integer number (40878964).

Almost surely, 2^81757927 is an apocalyptic number.

81757927 is a deficient number, since it is larger than the sum of its proper divisors (1).

81757927 is an equidigital number, since it uses as much as digits as its factorization.

81757927 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 246960, while the sum is 46.

The square root of 81757927 is about 9042.0090134881. The cubic root of 81757927 is about 434.0202143246.

The spelling of 81757927 in words is "eighty-one million, seven hundred fifty-seven thousand, nine hundred twenty-seven".