81947527 has 2 divisors, whose sum is σ = 81947528. Its totient is φ = 81947526.

The previous prime is 81947507. The next prime is 81947543. The reversal of 81947527 is 72574918.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 81947527 - 2¹⁹ = 81423239 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (81947507) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 40973763 + 40973764.

It is an arithmetic number, because the mean of its divisors is an integer number (40973764).

Almost surely, 2^81947527 is an apocalyptic number.

81947527 is a deficient number, since it is larger than the sum of its proper divisors (1).

81947527 is an equidigital number, since it uses as much as digits as its factorization.

81947527 is an evil number, because the sum of its binary digits is even.

The product of its digits is 141120, while the sum is 43.

The square root of 81947527 is about 9052.4873377431. The cubic root of 81947527 is about 434.3554588935.

The spelling of 81947527 in words is "eighty-one million, nine hundred forty-seven thousand, five hundred twenty-seven".