21420050121 has 24 divisors (see below), whose sum is σ = 33984525120. Its totient is φ = 12940256736.

The previous prime is 21420050111. The next prime is 21420050149. The reversal of 21420050121 is 12105002412.

21420050121 is a `hidden beast` number, since 2 + 142 + 0 + 0 + 501 + 21 = 666.

It is not a de Polignac number, because 21420050121 - 2¹⁰ = 21420049097 is a prime.

It is a super-2 number, since 2×21420050121² (a number of 21 digits) contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 21420050094 and 21420050103.

It is not an unprimeable number, because it can be changed into a prime (21420050111) 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, 2719186 + ... + 2727051.

It is an arithmetic number, because the mean of its divisors is an integer number (1416021880).

Almost surely, 2^21420050121 is an apocalyptic number.

It is an amenable number.

21420050121 is a deficient number, since it is larger than the sum of its proper divisors (12564474999).

21420050121 is a wasteful number, since it uses less digits than its factorization.

21420050121 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5446285 (or 5446282 counting only the distinct ones).

The product of its (nonzero) digits is 160, while the sum is 18.

Adding to 21420050121 its reverse (12105002412), we get a palindrome (33525052533).

The spelling of 21420050121 in words is "twenty-one billion, four hundred twenty million, fifty thousand, one hundred twenty-one".