21113302123 has 4 divisors (see below), whose sum is σ = 21511666368. Its totient is φ = 20714937880.

The previous prime is 21113302121. The next prime is 21113302169. The reversal of 21113302123 is 32120331112.

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 21113302123 - 2¹ = 21113302121 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 21113302123.

It is not an unprimeable number, because it can be changed into a prime (21113302121) 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, 199182043 + ... + 199182148.

It is an arithmetic number, because the mean of its divisors is an integer number (5377916592).

Almost surely, 2^21113302123 is an apocalyptic number.

21113302123 is a deficient number, since it is larger than the sum of its proper divisors (398364245).

21113302123 is an equidigital number, since it uses as much as digits as its factorization.

21113302123 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 398364244.

The product of its (nonzero) digits is 216, while the sum is 19.

Adding to 21113302123 its reverse (32120331112), we get a palindrome (53233633235).

The spelling of 21113302123 in words is "twenty-one billion, one hundred thirteen million, three hundred two thousand, one hundred twenty-three".