21494 has 8 divisors (see below), whose sum is σ = 35208. Its totient is φ = 9760.

The previous prime is 21493. The next prime is 21499. The reversal of 21494 is 49412.

It is a sphenic number, since it is the product of 3 distinct primes.

It is an Ulam number.

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

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21491) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 467 + ... + 510.

It is an arithmetic number, because the mean of its divisors is an integer number (4401).

2²¹⁴⁹⁴ is an apocalyptic number.

21494 is a deficient number, since it is larger than the sum of its proper divisors (13714).

21494 is a wasteful number, since it uses less digits than its factorization.

21494 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 990.

The product of its digits is 288, while the sum is 20.

The square root of 21494 is about 146.6083217283. The cubic root of 21494 is about 27.8039019418.

It can be divided in two parts, 21 and 494, that added together give a palindrome (515).

The spelling of 21494 in words is "twenty-one thousand, four hundred ninety-four".