123001210021 has 4 divisors (see below), whose sum is σ = 123004001772. Its totient is φ = 122998418272.

The previous prime is 123001209997. The next prime is 123001210027. The reversal of 123001210021 is 120012100321.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 117775944225 + 5225265796 = 343185^2 + 72286^2 .

It is a cyclic number.

It is not a de Polignac number, because 123001210021 - 2⁹ = 123001209509 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 123001209983 and 123001210010.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (123001210027) 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 3 ways as a sum of consecutive naturals, for example, 1328710 + ... + 1418263.

It is an arithmetic number, because the mean of its divisors is an integer number (30751000443).

Almost surely, 2^123001210021 is an apocalyptic number.

It is an amenable number.

123001210021 is a deficient number, since it is larger than the sum of its proper divisors (2791751).

123001210021 is an equidigital number, since it uses as much as digits as its factorization.

123001210021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2791750.

The product of its (nonzero) digits is 24, while the sum is 13.

Adding to 123001210021 its reverse (120012100321), we get a palindrome (243013310342).

The spelling of 123001210021 in words is "one hundred twenty-three billion, one million, two hundred ten thousand, twenty-one".