21154453124323 has 4 divisors (see below), whose sum is σ = 21264061689928. Its totient is φ = 21044844558720.

The previous prime is 21154453124317. The next prime is 21154453124351. The reversal of 21154453124323 is 32342135445112.

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

It is a cyclic number.

It is not a de Polignac number, because 21154453124323 - 2¹³ = 21154453116131 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21154453124353) 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, 54804282513 + ... + 54804282898.

It is an arithmetic number, because the mean of its divisors is an integer number (5316015422482).

Almost surely, 2^{21154453124323} is an apocalyptic number.

21154453124323 is a deficient number, since it is larger than the sum of its proper divisors (109608565605).

21154453124323 is a wasteful number, since it uses less digits than its factorization.

21154453124323 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 109608565604.

The product of its digits is 345600, while the sum is 40.

Adding to 21154453124323 its reverse (32342135445112), we get a palindrome (53496588569435).

The spelling of 21154453124323 in words is "twenty-one trillion, one hundred fifty-four billion, four hundred fifty-three million, one hundred twenty-four thousand, three hundred twenty-three".