21220212311 has 8 divisors (see below), whose sum is σ = 23243235120. Its totient is φ = 19283275648.

The previous prime is 21220212271. The next prime is 21220212317. The reversal of 21220212311 is 11321202212.

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21220212311 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (17).

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 21220212311.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21220212317) 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, 21521021 + ... + 21522006.

It is an arithmetic number, because the mean of its divisors is an integer number (2905404390).

Almost surely, 2^21220212311 is an apocalyptic number.

21220212311 is a deficient number, since it is larger than the sum of its proper divisors (2023022809).

21220212311 is a wasteful number, since it uses less digits than its factorization.

21220212311 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 43043073.

The product of its (nonzero) digits is 96, while the sum is 17.

Adding to 21220212311 its reverse (11321202212), we get a palindrome (32541414523).

The spelling of 21220212311 in words is "twenty-one billion, two hundred twenty million, two hundred twelve thousand, three hundred eleven".