25778 has 4 divisors (see below), whose sum is σ = 38670. Its totient is φ = 12888.

The previous prime is 25771. The next prime is 25793. The reversal of 25778 is 87752.

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., 20449 + 5329 = 143^2 + 73^2 .

It is a plaindrome in base 10.

It is a self number, because there is not a number n which added to its sum of digits gives 25778.

It is not an unprimeable number, because it can be changed into a prime (25771) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 6443 + ... + 6446.

2²⁵⁷⁷⁸ is an apocalyptic number.

25778 is a deficient number, since it is larger than the sum of its proper divisors (12892).

25778 is a wasteful number, since it uses less digits than its factorization.

25778 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 12891.

The product of its digits is 3920, while the sum is 29.

The square root of 25778 is about 160.5552864281. Note that the first 3 decimals coincide. The cubic root of 25778 is about 29.5404023637.

The spelling of 25778 in words is "twenty-five thousand, seven hundred seventy-eight".