123120401021 has 4 divisors (see below), whose sum is σ = 123142186332. Its totient is φ = 123098615712.

The previous prime is 123120401017. The next prime is 123120401039. The reversal of 123120401021 is 120104021321.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 120104021321 = 59369 ⋅2023009.

It can be written as a sum of positive squares in 2 ways, for example, as 69347428921 + 53772972100 = 263339^2 + 231890^2 .

It is a cyclic number.

It is not a de Polignac number, because 123120401021 - 2² = 123120401017 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 (123120400021) 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, 10884176 + ... + 10895481.

It is an arithmetic number, because the mean of its divisors is an integer number (30785546583).

Almost surely, 2^123120401021 is an apocalyptic number.

It is an amenable number.

123120401021 is a deficient number, since it is larger than the sum of its proper divisors (21785311).

123120401021 is an equidigital number, since it uses as much as digits as its factorization.

123120401021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 21785310.

The product of its (nonzero) digits is 96, while the sum is 17.

Adding to 123120401021 its reverse (120104021321), we get a palindrome (243224422342).

The spelling of 123120401021 in words is "one hundred twenty-three billion, one hundred twenty million, four hundred one thousand, twenty-one".