22978 has 4 divisors (see below), whose sum is σ = 34470. Its totient is φ = 11488.

The previous prime is 22973. The next prime is 22993. The reversal of 22978 is 87922.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 87922 = 2 ⋅43961.

It can be written as a sum of positive squares in only one way, i.e., 21609 + 1369 = 147^2 + 37^2 .

It is a d-powerful number, because it can be written as 2⁴ + 2¹⁴ + 9² + 7⁴ + 8⁴ .

It is a plaindrome in base 12.

It is not an unprimeable number, because it can be changed into a prime (22973) 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, 5743 + ... + 5746.

2²²⁹⁷⁸ is an apocalyptic number.

22978 is a deficient number, since it is larger than the sum of its proper divisors (11492).

22978 is a wasteful number, since it uses less digits than its factorization.

22978 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 11491.

The product of its digits is 2016, while the sum is 28.

The square root of 22978 is about 151.5849596761. The cubic root of 22978 is about 28.4295995040.

It can be divided in two parts, 22 and 978, that added together give a cube (1000 = 10³).

The spelling of 22978 in words is "twenty-two thousand, nine hundred seventy-eight".