81165967 has 8 divisors (see below), whose sum is σ = 88194560. Its totient is φ = 74413080.

The previous prime is 81165913. The next prime is 81165991. The reversal of 81165967 is 76956118.

It is a happy number.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-81165967 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81165907) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 68313 + ... + 69490.

It is an arithmetic number, because the mean of its divisors is an integer number (11024320).

Almost surely, 2^81165967 is an apocalyptic number.

81165967 is a deficient number, since it is larger than the sum of its proper divisors (7028593).

81165967 is a wasteful number, since it uses less digits than its factorization.

81165967 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 137853.

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

The square root of 81165967 is about 9009.2156706342. The cubic root of 81165967 is about 432.9701828643.

The spelling of 81165967 in words is "eighty-one million, one hundred sixty-five thousand, nine hundred sixty-seven".