81278 has 4 divisors (see below), whose sum is σ = 121920. Its totient is φ = 40638.

The previous prime is 81239. The next prime is 81281. The reversal of 81278 is 87218.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 87218 = 2 ⋅43609.

It is a super-2 number, since 2×81278² = 13212226568, which contains 22 as substring.

It is an alternating number because its digits alternate between even and odd.

It is a Curzon number.

It is a congruent number.

It is an unprimeable number.

81278 is an untouchable number, because it is not equal to the sum of proper divisors of any number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 20318 + ... + 20321.

It is an arithmetic number, because the mean of its divisors is an integer number (30480).

2⁸¹²⁷⁸ is an apocalyptic number.

81278 is a deficient number, since it is larger than the sum of its proper divisors (40642).

81278 is a wasteful number, since it uses less digits than its factorization.

81278 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 40641.

The product of its digits is 896, while the sum is 26.

The square root of 81278 is about 285.0929672931. The cubic root of 81278 is about 43.3169300177.

It can be divided in two parts, 812 and 78, that multiplied together give a palindrome (63336).

The spelling of 81278 in words is "eighty-one thousand, two hundred seventy-eight".