21464 has 8 divisors (see below), whose sum is σ = 40260. Its totient is φ = 10728.

The previous prime is 21433. The next prime is 21467. The reversal of 21464 is 46412.

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

It is a congruent number.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 21464.

It is not an unprimeable number, because it can be changed into a prime (21467) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1334 + ... + 1349.

2²¹⁴⁶⁴ is an apocalyptic number.

It is an amenable number.

21464 is a deficient number, since it is larger than the sum of its proper divisors (18796).

21464 is a wasteful number, since it uses less digits than its factorization.

21464 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2689 (or 2685 counting only the distinct ones).

The product of its digits is 192, while the sum is 17.

The square root of 21464 is about 146.5059725745. The cubic root of 21464 is about 27.7909602615.

Adding to 21464 its reverse (46412), we get a palindrome (67876).

The spelling of 21464 in words is "twenty-one thousand, four hundred sixty-four".