21213211023 has 12 divisors (see below), whose sum is σ = 30643404480. Its totient is φ = 14141171616.

The previous prime is 21213211021. The next prime is 21213211039. The reversal of 21213211023 is 32011231212.

It is not a de Polignac number, because 21213211023 - 2¹ = 21213211021 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 21213210987 and 21213211005.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21213211021) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 73363 + ... + 218651.

It is an arithmetic number, because the mean of its divisors is an integer number (2553617040).

Almost surely, 2^21213211023 is an apocalyptic number.

21213211023 is a deficient number, since it is larger than the sum of its proper divisors (9430193457).

21213211023 is a wasteful number, since it uses less digits than its factorization.

21213211023 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 161518 (or 161515 counting only the distinct ones).

The product of its (nonzero) digits is 144, while the sum is 18.

Adding to 21213211023 its reverse (32011231212), we get a palindrome (53224442235).

The spelling of 21213211023 in words is "twenty-one billion, two hundred thirteen million, two hundred eleven thousand, twenty-three".