81158647 has 2 divisors, whose sum is σ = 81158648. Its totient is φ = 81158646.

The previous prime is 81158621. The next prime is 81158653. The reversal of 81158647 is 74685118.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 81158647 - 2¹⁵ = 81125879 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (81158687) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 40579323 + 40579324.

It is an arithmetic number, because the mean of its divisors is an integer number (40579324).

Almost surely, 2^81158647 is an apocalyptic number.

81158647 is a deficient number, since it is larger than the sum of its proper divisors (1).

81158647 is an equidigital number, since it uses as much as digits as its factorization.

81158647 is an evil number, because the sum of its binary digits is even.

The product of its digits is 53760, while the sum is 40.

The square root of 81158647 is about 9008.8094107934. The cubic root of 81158647 is about 432.9571665836.

The spelling of 81158647 in words is "eighty-one million, one hundred fifty-eight thousand, six hundred forty-seven".