21123227454 has 128 divisors (see below), whose sum is σ = 50872320000. Its totient is φ = 5720682240.

The previous prime is 21123227449. The next prime is 21123227467. The reversal of 21123227454 is 45472232112.

It is a happy number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 14090797 + ... + 14092295.

It is an arithmetic number, because the mean of its divisors is an integer number (397440000).

Almost surely, 2^21123227454 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21123227454, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (25436160000).

21123227454 is an abundant number, since it is smaller than the sum of its proper divisors (29749092546).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21123227454 is a wasteful number, since it uses less digits than its factorization.

21123227454 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1758.

The product of its digits is 26880, while the sum is 33.

Adding to 21123227454 its reverse (45472232112), we get a palindrome (66595459566).

The spelling of 21123227454 in words is "twenty-one billion, one hundred twenty-three million, two hundred twenty-seven thousand, four hundred fifty-four".