20104 has 16 divisors (see below), whose sum is σ = 43200. Its totient is φ = 8592.

The previous prime is 20101. The next prime is 20107. The reversal of 20104 is 40102.

It is an interprime number because it is at equal distance from previous prime (20101) and next prime (20107).

It is a Harshad number since it is a multiple of its sum of digits (7).

It is a nialpdrome in base 12.

It is not an unprimeable number, because it can be changed into a prime (20101) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 124 + ... + 235.

It is an arithmetic number, because the mean of its divisors is an integer number (2700).

2²⁰¹⁰⁴ is an apocalyptic number.

It is an amenable number.

20104 is an abundant number, since it is smaller than the sum of its proper divisors (23096).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

It is a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (21600).

20104 is a wasteful number, since it uses less digits than its factorization.

20104 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 372 (or 368 counting only the distinct ones).

The product of its (nonzero) digits is 8, while the sum is 7.

The square root of 20104 is about 141.7885749981. The cubic root of 20104 is about 27.1911447529.

Adding to 20104 its reverse (40102), we get a palindrome (60206).

It can be divided in two parts, 20 and 104, that multiplied together give a triangular number (2080 = T₆₄).

The spelling of 20104 in words is "twenty thousand, one hundred four", and thus it is an iban number.