21420122453123 has 4 divisors (see below), whose sum is σ = 21477549055248. Its totient is φ = 21362695851000.

The previous prime is 21420122453111. The next prime is 21420122453143. The reversal of 21420122453123 is 32135422102412.

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21420122453123 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 21420122453123.

It is not an unprimeable number, because it can be changed into a prime (21420122453143) 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, 28713300503 + ... + 28713301248.

It is an arithmetic number, because the mean of its divisors is an integer number (5369387263812).

Almost surely, 2^{21420122453123} is an apocalyptic number.

21420122453123 is a deficient number, since it is larger than the sum of its proper divisors (57426602125).

21420122453123 is an equidigital number, since it uses as much as digits as its factorization.

21420122453123 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 57426602124.

The product of its (nonzero) digits is 23040, while the sum is 32.

Adding to 21420122453123 its reverse (32135422102412), we get a palindrome (53555544555535).

The spelling of 21420122453123 in words is "twenty-one trillion, four hundred twenty billion, one hundred twenty-two million, four hundred fifty-three thousand, one hundred twenty-three".