123400420121 has 16 divisors (see below), whose sum is σ = 135534679488. Its totient is φ = 111421248000.

The previous prime is 123400420081. The next prime is 123400420139. The reversal of 123400420121 is 121024004321.

It is a cyclic number.

It is not a de Polignac number, because 123400420121 - 2²² = 123396225817 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 123400420093 and 123400420102.

It is not an unprimeable number, because it can be changed into a prime (123400420181) 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 15 ways as a sum of consecutive naturals, for example, 967730 + ... + 1087796.

It is an arithmetic number, because the mean of its divisors is an integer number (8470917468).

Almost surely, 2^123400420121 is an apocalyptic number.

123400420121 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

It is an amenable number.

123400420121 is a deficient number, since it is larger than the sum of its proper divisors (12134259367).

123400420121 is a wasteful number, since it uses less digits than its factorization.

123400420121 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 120712.

The product of its (nonzero) digits is 384, while the sum is 20.

Adding to 123400420121 its reverse (121024004321), we get a palindrome (244424424442).

The spelling of 123400420121 in words is "one hundred twenty-three billion, four hundred million, four hundred twenty thousand, one hundred twenty-one".