82778 has 4 divisors (see below), whose sum is σ = 124170. Its totient is φ = 41388.

The previous prime is 82763. The next prime is 82781. The reversal of 82778 is 87728.

It is a happy number.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in only one way, i.e., 64009 + 18769 = 253^2 + 137^2 .

It is a plaindrome in base 14.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 20693 + ... + 20696.

2⁸²⁷⁷⁸ is an apocalyptic number.

82778 is a deficient number, since it is larger than the sum of its proper divisors (41392).

82778 is a wasteful number, since it uses less digits than its factorization.

82778 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 41391.

The product of its digits is 6272, while the sum is 32.

The square root of 82778 is about 287.7116612166. The cubic root of 82778 is about 43.5817812387.

Subtracting 82778 from its reverse (87728), we obtain a triangular number (4950 = T₉₉).

The spelling of 82778 in words is "eighty-two thousand, seven hundred seventy-eight".