81565067 has 2 divisors, whose sum is σ = 81565068. Its totient is φ = 81565066.

The previous prime is 81565049. The next prime is 81565073. The reversal of 81565067 is 76056518.

It is a happy number.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 81565067 - 2¹² = 81560971 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 81565067.

It is not a weakly prime, because it can be changed into another prime (81565007) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 40782533 + 40782534.

It is an arithmetic number, because the mean of its divisors is an integer number (40782534).

Almost surely, 2^81565067 is an apocalyptic number.

81565067 is a deficient number, since it is larger than the sum of its proper divisors (1).

81565067 is an equidigital number, since it uses as much as digits as its factorization.

81565067 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 50400, while the sum is 38.

The square root of 81565067 is about 9031.3380514739. The cubic root of 81565067 is about 433.6786733643.

The spelling of 81565067 in words is "eighty-one million, five hundred sixty-five thousand, sixty-seven".