21100131223 has 4 divisors (see below), whose sum is σ = 21103174600. Its totient is φ = 21097087848.

The previous prime is 21100131203. The next prime is 21100131259. The reversal of 21100131223 is 32213100112.

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 21100131223 - 2¹⁷ = 21100000151 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21100131197 and 21100131206.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21100131203) 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, 1511265 + ... + 1525162.

It is an arithmetic number, because the mean of its divisors is an integer number (5275793650).

Almost surely, 2^21100131223 is an apocalyptic number.

21100131223 is a deficient number, since it is larger than the sum of its proper divisors (3043377).

21100131223 is an equidigital number, since it uses as much as digits as its factorization.

21100131223 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3043376.

The product of its (nonzero) digits is 72, while the sum is 16.

Adding to 21100131223 its reverse (32213100112), we get a palindrome (53313231335).

The spelling of 21100131223 in words is "twenty-one billion, one hundred million, one hundred thirty-one thousand, two hundred twenty-three".