21001220222111 has 8 divisors (see below), whose sum is σ = 21725775603120. Its totient is φ = 20276689866048.

The previous prime is 21001220222057. The next prime is 21001220222119. The reversal of 21001220222111 is 11122202210012.

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

It is a cyclic number.

It is not a de Polignac number, because 21001220222111 - 2¹⁴ = 21001220205727 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 21001220222111.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21001220222119) 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, 4540886 + ... + 7913411.

It is an arithmetic number, because the mean of its divisors is an integer number (2715721950390).

Almost surely, 2^{21001220222111} is an apocalyptic number.

21001220222111 is a deficient number, since it is larger than the sum of its proper divisors (724555381009).

21001220222111 is a wasteful number, since it uses less digits than its factorization.

21001220222111 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 12512473.

The product of its (nonzero) digits is 64, while the sum is 17.

Adding to 21001220222111 its reverse (11122202210012), we get a palindrome (32123422432123).

The spelling of 21001220222111 in words is "twenty-one trillion, one billion, two hundred twenty million, two hundred twenty-two thousand, one hundred eleven".