21454051121 has 4 divisors (see below), whose sum is σ = 21495230244. Its totient is φ = 21412872000.

The previous prime is 21454051117. The next prime is 21454051123. The reversal of 21454051121 is 12115045412.

It is a happy number.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 11807864896 + 9646186225 = 108664^2 + 98215^2 .

It is a cyclic number.

It is not a de Polignac number, because 21454051121 - 2² = 21454051117 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21454051123) 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, 20588780 + ... + 20589821.

It is an arithmetic number, because the mean of its divisors is an integer number (5373807561).

Almost surely, 2^21454051121 is an apocalyptic number.

It is an amenable number.

21454051121 is a deficient number, since it is larger than the sum of its proper divisors (41179123).

21454051121 is an equidigital number, since it uses as much as digits as its factorization.

21454051121 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 41179122.

The product of its (nonzero) digits is 1600, while the sum is 26.

Adding to 21454051121 its reverse (12115045412), we get a palindrome (33569096533).

The spelling of 21454051121 in words is "twenty-one billion, four hundred fifty-four million, fifty-one thousand, one hundred twenty-one".