20546 has 4 divisors (see below), whose sum is σ = 30822. Its totient is φ = 10272.

The previous prime is 20543. The next prime is 20549. The reversal of 20546 is 64502.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 64502 = 2 ⋅32251.

It is an interprime number because it is at equal distance from previous prime (20543) and next prime (20549).

It can be written as a sum of positive squares in only one way, i.e., 19321 + 1225 = 139^2 + 35^2 .

It is a plaindrome in base 11.

It is a nialpdrome in base 12.

It is not an unprimeable number, because it can be changed into a prime (20543) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5135 + ... + 5138.

2²⁰⁵⁴⁶ is an apocalyptic number.

20546 is a deficient number, since it is larger than the sum of its proper divisors (10276).

20546 is a wasteful number, since it uses less digits than its factorization.

20546 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10275.

The product of its (nonzero) digits is 240, while the sum is 17.

The square root of 20546 is about 143.3387595872. The cubic root of 20546 is about 27.3889738433.

Subtracting 20546 from its reverse (64502), we obtain a triangular number (43956 = T₂₉₆).

The spelling of 20546 in words is "twenty thousand, five hundred forty-six".