123021 has 6 divisors (see below), whose sum is σ = 177710. Its totient is φ = 82008.

The previous prime is 123017. The next prime is 123031. The reversal of 123021 is 120321.

It is a happy number.

It can be written as a sum of positive squares in only one way, i.e., 114921 + 8100 = 339^2 + 90^2 .

It is not a de Polignac number, because 123021 - 2² = 123017 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (9), and also a Moran number because the ratio is a prime number: 13669 = 123021 / (1 + 2 + 3 + 0 + 2 + 1).

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 122994 and 123012.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (123001) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 6826 + ... + 6843.

2¹²³⁰²¹ is an apocalyptic number.

It is an amenable number.

123021 is a deficient number, since it is larger than the sum of its proper divisors (54689).

123021 is a wasteful number, since it uses less digits than its factorization.

123021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 13675 (or 13672 counting only the distinct ones).

The product of its (nonzero) digits is 12, while the sum is 9.

The square root of 123021 is about 350.7434960195. The cubic root of 123021 is about 49.7347284423.

Adding to 123021 its reverse (120321), we get a palindrome (243342).

The spelling of 123021 in words is "one hundred twenty-three thousand, twenty-one", and thus it is an iban number.