123443021 has 8 divisors (see below), whose sum is σ = 133073304. Its totient is φ = 113832000.

The previous prime is 123442987. The next prime is 123443027. The reversal of 123443021 is 120344321.

It can be written as a sum of positive squares in 4 ways, for example, as 13402921 + 110040100 = 3661^2 + 10490^2 .

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-123443021 is a prime.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 123442984 and 123443002.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (123443027) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 10271 + ... + 18771.

It is an arithmetic number, because the mean of its divisors is an integer number (16634163).

Almost surely, 2^123443021 is an apocalyptic number.

It is an amenable number.

123443021 is a deficient number, since it is larger than the sum of its proper divisors (9630283).

123443021 is a wasteful number, since it uses less digits than its factorization.

123443021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9631.

The product of its (nonzero) digits is 576, while the sum is 20.

The square root of 123443021 is about 11110.4914832783. The cubic root of 123443021 is about 497.9153485358.

Adding to 123443021 its reverse (120344321), we get a palindrome (243787342).

The spelling of 123443021 in words is "one hundred twenty-three million, four hundred forty-three thousand, twenty-one".