21220031023 has 4 divisors (see below), whose sum is σ = 22468268160. Its totient is φ = 19971793888.

The previous prime is 21220031011. The next prime is 21220031059. The reversal of 21220031023 is 32013002212.

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 21220031023 - 2⁵ = 21220030991 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21220030988 and 21220031006.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21220031083) 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, 624118543 + ... + 624118576.

It is an arithmetic number, because the mean of its divisors is an integer number (5617067040).

Almost surely, 2^21220031023 is an apocalyptic number.

21220031023 is a deficient number, since it is larger than the sum of its proper divisors (1248237137).

21220031023 is a wasteful number, since it uses less digits than its factorization.

21220031023 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1248237136.

The product of its (nonzero) digits is 144, while the sum is 16.

Adding to 21220031023 its reverse (32013002212), we get a palindrome (53233033235).

The spelling of 21220031023 in words is "twenty-one billion, two hundred twenty million, thirty-one thousand, twenty-three".