21124221213 has 8 divisors (see below), whose sum is σ = 28249207168. Its totient is φ = 14041024704.

The previous prime is 21124221179. The next prime is 21124221271. The reversal of 21124221213 is 31212242112.

It is a happy number.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 21124221213 - 2²⁵ = 21090666781 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 21124221213.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21124223213) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 10446181 + ... + 10448202.

It is an arithmetic number, because the mean of its divisors is an integer number (3531150896).

Almost surely, 2^21124221213 is an apocalyptic number.

It is an amenable number.

21124221213 is a deficient number, since it is larger than the sum of its proper divisors (7124985955).

21124221213 is a wasteful number, since it uses less digits than its factorization.

21124221213 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 20894723.

The product of its digits is 384, while the sum is 21.

Adding to 21124221213 its reverse (31212242112), we get a palindrome (52336463325).

The spelling of 21124221213 in words is "twenty-one billion, one hundred twenty-four million, two hundred twenty-one thousand, two hundred thirteen".