21423100121 has 4 divisors (see below), whose sum is σ = 21742847952. Its totient is φ = 21103352292.

The previous prime is 21423100099. The next prime is 21423100129. The reversal of 21423100121 is 12100132412.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 21423100121 - 2¹⁰ = 21423099097 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 21423100121.

It is not an unprimeable number, because it can be changed into a prime (21423100129) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 159873815 + ... + 159873948.

It is an arithmetic number, because the mean of its divisors is an integer number (5435711988).

Almost surely, 2^21423100121 is an apocalyptic number.

It is an amenable number.

21423100121 is a deficient number, since it is larger than the sum of its proper divisors (319747831).

21423100121 is an equidigital number, since it uses as much as digits as its factorization.

21423100121 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 319747830.

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

Adding to 21423100121 its reverse (12100132412), we get a palindrome (33523232533).

The spelling of 21423100121 in words is "twenty-one billion, four hundred twenty-three million, one hundred thousand, one hundred twenty-one".