21320020311 has 4 divisors (see below), whose sum is σ = 28426693752. Its totient is φ = 14213346872.

The previous prime is 21320020273. The next prime is 21320020349. The reversal of 21320020311 is 11302002312.

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

It is an interprime number because it is at equal distance from previous prime (21320020273) and next prime (21320020349).

It is a cyclic number.

It is not a de Polignac number, because 21320020311 - 2⁶ = 21320020247 is a prime.

It is a super-2 number, since 2×21320020311² (a number of 21 digits) contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21320020811) 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, 3553336716 + ... + 3553336721.

It is an arithmetic number, because the mean of its divisors is an integer number (7106673438).

Almost surely, 2^21320020311 is an apocalyptic number.

21320020311 is a deficient number, since it is larger than the sum of its proper divisors (7106673441).

21320020311 is an equidigital number, since it uses as much as digits as its factorization.

21320020311 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7106673440.

The product of its (nonzero) digits is 72, while the sum is 15.

Adding to 21320020311 its reverse (11302002312), we get a palindrome (32622022623).

The spelling of 21320020311 in words is "twenty-one billion, three hundred twenty million, twenty thousand, three hundred eleven".