21221322213 has 32 divisors (see below), whose sum is σ = 35765959936. Its totient is φ = 10891127808.

The previous prime is 21221322179. The next prime is 21221322233. The reversal of 21221322213 is 31222312212.

It is not a de Polignac number, because 21221322213 - 2¹² = 21221318117 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (21).

It is a self number, because there is not a number n which added to its sum of digits gives 21221322213.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21221322233) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 1040356 + ... + 1060557.

It is an arithmetic number, because the mean of its divisors is an integer number (1117686248).

Almost surely, 2^21221322213 is an apocalyptic number.

It is an amenable number.

21221322213 is a deficient number, since it is larger than the sum of its proper divisors (14544637723).

21221322213 is a wasteful number, since it uses less digits than its factorization.

21221322213 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2100973.

The product of its digits is 576, while the sum is 21.

Adding to 21221322213 its reverse (31222312212), we get a palindrome (52443634425).

The spelling of 21221322213 in words is "twenty-one billion, two hundred twenty-one million, three hundred twenty-two thousand, two hundred thirteen".