123123120021 has 24 divisors (see below), whose sum is σ = 196744766400. Its totient is φ = 73569081600.

The previous prime is 123123119981. The next prime is 123123120049. The reversal of 123123120021 is 120021321321.

123123120021 is a `hidden beast` number, since 1 + 231 + 231 + 200 + 2 + 1 = 666.

It is not a de Polignac number, because 123123120021 - 2²⁹ = 122586249109 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 123123119976 and 123123120003.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (123123120121) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 8751196 + ... + 8765253.

It is an arithmetic number, because the mean of its divisors is an integer number (8197698600).

Almost surely, 2^123123120021 is an apocalyptic number.

123123120021 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

It is an amenable number.

123123120021 is a deficient number, since it is larger than the sum of its proper divisors (73621646379).

123123120021 is a wasteful number, since it uses less digits than its factorization.

123123120021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 17516537 (or 17516534 counting only the distinct ones).

The product of its (nonzero) digits is 144, while the sum is 18.

Adding to 123123120021 its reverse (120021321321), we get a palindrome (243144441342).

The spelling of 123123120021 in words is "one hundred twenty-three billion, one hundred twenty-three million, one hundred twenty thousand, twenty-one".