124821 has 20 divisors (see below), whose sum is σ = 197472. Its totient is φ = 78408.

The previous prime is 124819. The next prime is 124823. The reversal of 124821 is 128421.

It is an interprime number because it is at equal distance from previous prime (124819) and next prime (124823).

It is not a de Polignac number, because 124821 - 2¹ = 124819 is a prime.

It is a plaindrome in base 14.

It is a junction number, because it is equal to n+sod(n) for n = 124794 and 124803.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (124823) 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 19 ways as a sum of consecutive naturals, for example, 1830 + ... + 1896.

2¹²⁴⁸²¹ is an apocalyptic number.

It is an amenable number.

124821 is a deficient number, since it is larger than the sum of its proper divisors (72651).

124821 is an equidigital number, since it uses as much as digits as its factorization.

124821 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 102 (or 93 counting only the distinct ones).

The product of its digits is 128, while the sum is 18.

The square root of 124821 is about 353.3001556750. The cubic root of 124821 is about 49.9761219319.

Subtracting 124821 from its reverse (128421), we obtain a square (3600 = 60²).

The spelling of 124821 in words is "one hundred twenty-four thousand, eight hundred twenty-one".