20461 has 8 divisors (see below), whose sum is σ = 24320. Its totient is φ = 16848.

The previous prime is 20443. The next prime is 20477. The reversal of 20461 is 16402.

20461 = T₁₃ + T₁₄ + ... + T₄₉.

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

It is a cyclic number.

It is not a de Polignac number, because 20461 - 2⁷ = 20333 is a prime.

It is a Duffinian number.

20461 is a lucky number.

It is a nialpdrome in base 12.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20411) by changing a digit.

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, 220 + ... + 298.

It is an arithmetic number, because the mean of its divisors is an integer number (3040).

2²⁰⁴⁶¹ is an apocalyptic number.

It is an amenable number.

20461 is a deficient number, since it is larger than the sum of its proper divisors (3859).

20461 is an equidigital number, since it uses as much as digits as its factorization.

20461 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 123.

The product of its (nonzero) digits is 48, while the sum is 13.

The square root of 20461 is about 143.0419518882. The cubic root of 20461 is about 27.3511517105.

Adding to 20461 its reverse (16402), we get a palindrome (36863).

The spelling of 20461 in words is "twenty thousand, four hundred sixty-one".