81115967 has 2 divisors, whose sum is σ = 81115968. Its totient is φ = 81115966.

The previous prime is 81115961. The next prime is 81116041. The reversal of 81115967 is 76951118.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 81115967 - 2¹² = 81111871 is a prime.

It is a Chen prime.

It is a self number, because there is not a number n which added to its sum of digits gives 81115967.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (81115961) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 40557983 + 40557984.

It is an arithmetic number, because the mean of its divisors is an integer number (40557984).

Almost surely, 2^81115967 is an apocalyptic number.

81115967 is a deficient number, since it is larger than the sum of its proper divisors (1).

81115967 is an equidigital number, since it uses as much as digits as its factorization.

81115967 is an evil number, because the sum of its binary digits is even.

The product of its digits is 15120, while the sum is 38.

The square root of 81115967 is about 9006.4403068027. The cubic root of 81115967 is about 432.8812582539.

The spelling of 81115967 in words is "eighty-one million, one hundred fifteen thousand, nine hundred sixty-seven".