81568 has 12 divisors (see below), whose sum is σ = 160650. Its totient is φ = 40768.

The previous prime is 81563. The next prime is 81569. The reversal of 81568 is 86518.

It is a happy number.

It can be written as a sum of positive squares in only one way, i.e., 51984 + 29584 = 228^2 + 172^2 .

It is not an unprimeable number, because it can be changed into a prime (81563) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1243 + ... + 1306.

2⁸¹⁵⁶⁸ is an apocalyptic number.

It is an amenable number.

81568 is a deficient number, since it is larger than the sum of its proper divisors (79082).

81568 is a wasteful number, since it uses less digits than its factorization.

81568 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2559 (or 2551 counting only the distinct ones).

The product of its digits is 1920, while the sum is 28.

The square root of 81568 is about 285.6011204460. The cubic root of 81568 is about 43.3683871522.

Subtracting 81568 from its reverse (86518), we obtain a triangular number (4950 = T₉₉).

It can be divided in two parts, 8 and 1568, that multiplied together give a square (12544 = 112²).

The spelling of 81568 in words is "eighty-one thousand, five hundred sixty-eight".