20968 has 8 divisors (see below), whose sum is σ = 39330. Its totient is φ = 10480.

The previous prime is 20963. The next prime is 20981. The reversal of 20968 is 86902.

It can be written as a sum of positive squares in only one way, i.e., 14884 + 6084 = 122^2 + 78^2 .

It is a tau number, because it is divible by the number of its divisors (8).

It is an Ulam number.

It is not an unprimeable number, because it can be changed into a prime (20963) 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, 1303 + ... + 1318.

2²⁰⁹⁶⁸ is an apocalyptic number.

It is an amenable number.

20968 is a deficient number, since it is larger than the sum of its proper divisors (18362).

20968 is a wasteful number, since it uses less digits than its factorization.

20968 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2627 (or 2623 counting only the distinct ones).

The product of its (nonzero) digits is 864, while the sum is 25.

The square root of 20968 is about 144.8033148792. The cubic root of 20968 is about 27.5752210567.

The spelling of 20968 in words is "twenty thousand, nine hundred sixty-eight".