21045414121 has 4 divisors (see below), whose sum is σ = 21055737600. Its totient is φ = 21035090644.

The previous prime is 21045414109. The next prime is 21045414157. The reversal of 21045414121 is 12141454012.

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 21045414121 - 2²⁷ = 20911196393 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21045414101) 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, 5158681 + ... + 5162758.

It is an arithmetic number, because the mean of its divisors is an integer number (5263934400).

Almost surely, 2^21045414121 is an apocalyptic number.

It is an amenable number.

21045414121 is a deficient number, since it is larger than the sum of its proper divisors (10323479).

21045414121 is a wasteful number, since it uses less digits than its factorization.

21045414121 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10323478.

The product of its (nonzero) digits is 1280, while the sum is 25.

Adding to 21045414121 its reverse (12141454012), we get a palindrome (33186868133).

The spelling of 21045414121 in words is "twenty-one billion, forty-five million, four hundred fourteen thousand, one hundred twenty-one".