21101223023 has 4 divisors (see below), whose sum is σ = 21114114840. Its totient is φ = 21088331208.

The previous prime is 21101223001. The next prime is 21101223041. The reversal of 21101223023 is 32032210112.

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 21101223023 - 2⁸ = 21101222767 is a prime.

It is a super-2 number, since 2×21101223023² (a number of 21 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 = 21101222992 and 21101223010.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21101223323) 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, 6443453 + ... + 6446726.

It is an arithmetic number, because the mean of its divisors is an integer number (5278528710).

Almost surely, 2^21101223023 is an apocalyptic number.

21101223023 is a deficient number, since it is larger than the sum of its proper divisors (12891817).

21101223023 is a wasteful number, since it uses less digits than its factorization.

21101223023 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 12891816.

The product of its (nonzero) digits is 144, while the sum is 17.

Adding to 21101223023 its reverse (32032210112), we get a palindrome (53133433135).

The spelling of 21101223023 in words is "twenty-one billion, one hundred one million, two hundred twenty-three thousand, twenty-three".