81959047 has 2 divisors, whose sum is σ = 81959048. Its totient is φ = 81959046.

The previous prime is 81959029. The next prime is 81959077. The reversal of 81959047 is 74095918.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 81959047 - 2¹¹ = 81956999 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 81958994 and 81959012.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (81959077) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 40979523 + 40979524.

It is an arithmetic number, because the mean of its divisors is an integer number (40979524).

Almost surely, 2^81959047 is an apocalyptic number.

81959047 is a deficient number, since it is larger than the sum of its proper divisors (1).

81959047 is an equidigital number, since it uses as much as digits as its factorization.

81959047 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 90720, while the sum is 43.

The square root of 81959047 is about 9053.1236045908. The cubic root of 81959047 is about 434.3758115127.

The spelling of 81959047 in words is "eighty-one million, nine hundred fifty-nine thousand, forty-seven".