20470 has 16 divisors (see below), whose sum is σ = 38880. Its totient is φ = 7744.

The previous prime is 20443. The next prime is 20477. The reversal of 20470 is 7402.

It is a nialpdrome in base 14.

It is a self number, because there is not a number n which added to its sum of digits gives 20470.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20477) by changing a digit.

20470 is an untouchable number, because it is not equal to the sum of proper divisors of any number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 186 + ... + 274.

It is an arithmetic number, because the mean of its divisors is an integer number (2430).

2²⁰⁴⁷⁰ is an apocalyptic number.

20470 is a deficient number, since it is larger than the sum of its proper divisors (18410).

20470 is a wasteful number, since it uses less digits than its factorization.

20470 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 119.

The product of its (nonzero) digits is 56, while the sum is 13.

The square root of 20470 is about 143.0734077318. The cubic root of 20470 is about 27.3551613595.

Adding to 20470 its reverse (7402), we get a palindrome (27872).

The spelling of 20470 in words is "twenty thousand, four hundred seventy", and thus it is an iban number.