21421041121 has 4 divisors (see below), whose sum is σ = 21919204912. Its totient is φ = 20922877332.

The previous prime is 21421041091. The next prime is 21421041127. The reversal of 21421041121 is 12114012412.

It is a happy number.

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 21421041121 - 2¹³ = 21421032929 is a prime.

It is a super-2 number, since 2×21421041121² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21421041127) 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, 249081831 + ... + 249081916.

It is an arithmetic number, because the mean of its divisors is an integer number (5479801228).

Almost surely, 2^21421041121 is an apocalyptic number.

It is an amenable number.

21421041121 is a deficient number, since it is larger than the sum of its proper divisors (498163791).

21421041121 is an equidigital number, since it uses as much as digits as its factorization.

21421041121 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 498163790.

The product of its (nonzero) digits is 128, while the sum is 19.

Adding to 21421041121 its reverse (12114012412), we get a palindrome (33535053533).

The spelling of 21421041121 in words is "twenty-one billion, four hundred twenty-one million, forty-one thousand, one hundred twenty-one".