21220220311 has 4 divisors (see below), whose sum is σ = 21221221624. Its totient is φ = 21219219000.

The previous prime is 21220220299. The next prime is 21220220317. The reversal of 21220220311 is 11302202212.

It is a happy number.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 21220220311 - 2¹¹ = 21220218263 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21220220317) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 468165 + ... + 511486.

It is an arithmetic number, because the mean of its divisors is an integer number (5305305406).

Almost surely, 2^21220220311 is an apocalyptic number.

21220220311 is a deficient number, since it is larger than the sum of its proper divisors (1001313).

21220220311 is an equidigital number, since it uses as much as digits as its factorization.

21220220311 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1001312.

The product of its (nonzero) digits is 96, while the sum is 16.

Adding to 21220220311 its reverse (11302202212), we get a palindrome (32522422523).

The spelling of 21220220311 in words is "twenty-one billion, two hundred twenty million, two hundred twenty thousand, three hundred eleven".