81568169 has 8 divisors (see below), whose sum is σ = 82420512. Its totient is φ = 80720640.

The previous prime is 81568153. The next prime is 81568177. The reversal of 81568169 is 96186518.

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

It is a cyclic number.

It is not a de Polignac number, because 81568169 - 2⁴ = 81568153 is a prime.

It is a super-2 number, since 2×81568169² = 13306732388025122, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (81568129) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 39722 + ... + 41724.

It is an arithmetic number, because the mean of its divisors is an integer number (10302564).

Almost surely, 2^81568169 is an apocalyptic number.

It is an amenable number.

81568169 is a deficient number, since it is larger than the sum of its proper divisors (852343).

81568169 is a wasteful number, since it uses less digits than its factorization.

81568169 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2407.

The product of its digits is 103680, while the sum is 44.

The square root of 81568169 is about 9031.5097851910. The cubic root of 81568169 is about 433.6841710373.

The spelling of 81568169 in words is "eighty-one million, five hundred sixty-eight thousand, one hundred sixty-nine".