21103313122123 has 4 divisors (see below), whose sum is σ = 21831013574640. Its totient is φ = 20375612669608.

The previous prime is 21103313122117. The next prime is 21103313122127. The reversal of 21103313122123 is 32122131330112.

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-21103313122123 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21103313122127) 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, 363850226215 + ... + 363850226272.

It is an arithmetic number, because the mean of its divisors is an integer number (5457753393660).

Almost surely, 2^{21103313122123} is an apocalyptic number.

21103313122123 is a deficient number, since it is larger than the sum of its proper divisors (727700452517).

21103313122123 is an equidigital number, since it uses as much as digits as its factorization.

21103313122123 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 727700452516.

The product of its (nonzero) digits is 1296, while the sum is 25.

Adding to 21103313122123 its reverse (32122131330112), we get a palindrome (53225444452235).

The spelling of 21103313122123 in words is "twenty-one trillion, one hundred three billion, three hundred thirteen million, one hundred twenty-two thousand, one hundred twenty-three".