123020021213 has 4 divisors (see below), whose sum is σ = 127262090940. Its totient is φ = 118777951488.

The previous prime is 123020021209. The next prime is 123020021233. The reversal of 123020021213 is 312120020321.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 312120020321 = 2129 ⋅146604049.

It can be written as a sum of positive squares in 2 ways, for example, as 102587605849 + 20432415364 = 320293^2 + 142942^2 .

It is a cyclic number.

It is not a de Polignac number, because 123020021213 - 2² = 123020021209 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 123020021191 and 123020021200.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (123020021203) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2121034820 + ... + 2121034877.

It is an arithmetic number, because the mean of its divisors is an integer number (31815522735).

Almost surely, 2^123020021213 is an apocalyptic number.

It is an amenable number.

123020021213 is a deficient number, since it is larger than the sum of its proper divisors (4242069727).

123020021213 is an equidigital number, since it uses as much as digits as its factorization.

123020021213 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4242069726.

The product of its (nonzero) digits is 144, while the sum is 17.

Adding to 123020021213 its reverse (312120020321), we get a palindrome (435140041534).

The spelling of 123020021213 in words is "one hundred twenty-three billion, twenty million, twenty-one thousand, two hundred thirteen".