81568071 has 24 divisors (see below), whose sum is σ = 127458240. Its totient is φ = 49968576.

The previous prime is 81568049. The next prime is 81568073. The reversal of 81568071 is 17086518.

It is not a de Polignac number, because 81568071 - 2¹⁸ = 81305927 is a prime.

It is a super-2 number, since 2×81568071² = 13306700413322082, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81568073) 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 23 ways as a sum of consecutive naturals, for example, 26505 + ... + 29421.

It is an arithmetic number, because the mean of its divisors is an integer number (5310760).

Almost surely, 2^81568071 is an apocalyptic number.

81568071 is a deficient number, since it is larger than the sum of its proper divisors (45890169).

81568071 is a wasteful number, since it uses less digits than its factorization.

81568071 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3175 (or 3172 counting only the distinct ones).

The product of its (nonzero) digits is 13440, while the sum is 36.

The square root of 81568071 is about 9031.5043597399. The cubic root of 81568071 is about 433.6839973541.

It can be divided in two parts, 815 and 68071, that added together give a palindrome (68886).

The spelling of 81568071 in words is "eighty-one million, five hundred sixty-eight thousand, seventy-one".