21101220113123 has 4 divisors (see below), whose sum is σ = 21123362002968. Its totient is φ = 21079078223280.

The previous prime is 21101220113053. The next prime is 21101220113143. The reversal of 21101220113123 is 32131102210112.

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 21101220113123 - 2¹⁸ = 21101219850979 is a prime.

It is a super-2 number, since 2×21101220113123² (a number of 27 digits) contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21101220113095 and 21101220113104.

It is not an unprimeable number, because it can be changed into a prime (21101220113143) 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, 11070943493 + ... + 11070945398.

It is an arithmetic number, because the mean of its divisors is an integer number (5280840500742).

Almost surely, 2^{21101220113123} is an apocalyptic number.

21101220113123 is a deficient number, since it is larger than the sum of its proper divisors (22141889845).

21101220113123 is an equidigital number, since it uses as much as digits as its factorization.

21101220113123 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 22141889844.

The product of its (nonzero) digits is 144, while the sum is 20.

Adding to 21101220113123 its reverse (32131102210112), we get a palindrome (53232322323235).

The spelling of 21101220113123 in words is "twenty-one trillion, one hundred one billion, two hundred twenty million, one hundred thirteen thousand, one hundred twenty-three".