20974 has 4 divisors (see below), whose sum is σ = 31464. Its totient is φ = 10486.

The previous prime is 20963. The next prime is 20981. The reversal of 20974 is 47902.

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

It is a Smith number, since the sum of its digits (22) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a congruent number.

It is an unprimeable number.

20974 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, 5242 + ... + 5245.

It is an arithmetic number, because the mean of its divisors is an integer number (7866).

2²⁰⁹⁷⁴ is an apocalyptic number.

20974 is a deficient number, since it is larger than the sum of its proper divisors (10490).

20974 is a wasteful number, since it uses less digits than its factorization.

20974 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10489.

The product of its (nonzero) digits is 504, while the sum is 22.

The square root of 20974 is about 144.8240311551. The cubic root of 20974 is about 27.5778510253.

The spelling of 20974 in words is "twenty thousand, nine hundred seventy-four".