123403210421 has 4 divisors (see below), whose sum is σ = 123404140332. Its totient is φ = 123402280512.

The previous prime is 123403210391. The next prime is 123403210453. The reversal of 123403210421 is 124012304321.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length, and also an emirpimes, since its reverse is a distinct semiprime: 124012304321 = 116791 ⋅1061831.

It can be written as a sum of positive squares in 2 ways, for example, as 116973576196 + 6429634225 = 342014^2 + 80185^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-123403210421 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (123403215421) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 224420 + ... + 545133.

It is an arithmetic number, because the mean of its divisors is an integer number (30851035083).

Almost surely, 2^123403210421 is an apocalyptic number.

It is an amenable number.

123403210421 is a deficient number, since it is larger than the sum of its proper divisors (929911).

123403210421 is an equidigital number, since it uses as much as digits as its factorization.

123403210421 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 929910.

The product of its (nonzero) digits is 1152, while the sum is 23.

Adding to 123403210421 its reverse (124012304321), we get a palindrome (247415514742).

The spelling of 123403210421 in words is "one hundred twenty-three billion, four hundred three million, two hundred ten thousand, four hundred twenty-one".