20464 has 10 divisors (see below), whose sum is σ = 39680. Its totient is φ = 10224.

The previous prime is 20443. The next prime is 20477. The reversal of 20464 is 46402.

It is a Harshad number since it is a multiple of its sum of digits (16), and also a Moran number because the ratio is a prime number: 1279 = 20464 / (2 + 0 + 4 + 6 + 4).

It is a congruent number.

It is an unprimeable number.

20464 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, 624 + ... + 655.

It is an arithmetic number, because the mean of its divisors is an integer number (3968).

2²⁰⁴⁶⁴ is an apocalyptic number.

It is an amenable number.

20464 is a deficient number, since it is larger than the sum of its proper divisors (19216).

20464 is a wasteful number, since it uses less digits than its factorization.

20464 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1287 (or 1281 counting only the distinct ones).

The product of its (nonzero) digits is 192, while the sum is 16.

The square root of 20464 is about 143.0524379380. The cubic root of 20464 is about 27.3524883908.

Adding to 20464 its reverse (46402), we get a palindrome (66866).

It can be divided in two parts, 20 and 464, that added together give a palindrome (484).

The spelling of 20464 in words is "twenty thousand, four hundred sixty-four".