21076 has 12 divisors (see below), whose sum is σ = 40320. Its totient is φ = 9560.

The previous prime is 21067. The next prime is 21089. The reversal of 21076 is 67012.

It is an alternating number because its digits alternate between even and odd.

It is a congruent number.

It is an unprimeable number.

21076 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 in 3 ways as a sum of consecutive naturals, for example, 196 + ... + 283.

It is an arithmetic number, because the mean of its divisors is an integer number (3360).

2²¹⁰⁷⁶ is an apocalyptic number.

It is an amenable number.

21076 is a deficient number, since it is larger than the sum of its proper divisors (19244).

21076 is a wasteful number, since it uses less digits than its factorization.

21076 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 494 (or 492 counting only the distinct ones).

The product of its (nonzero) digits is 84, while the sum is 16.

The square root of 21076 is about 145.1757555517. The cubic root of 21076 is about 27.6224839542.

Adding to 21076 its reverse (67012), we get a palindrome (88088).

The spelling of 21076 in words is "twenty-one thousand, seventy-six".