21310305511 has 32 divisors (see below), whose sum is σ = 25317411840. Its totient is φ = 17714649600.

The previous prime is 21310305493. The next prime is 21310305553. The reversal of 21310305511 is 11550301312.

It is a cyclic number.

It is not a de Polignac number, because 21310305511 - 2⁹ = 21310304999 is a prime.

It is a super-2 number, since 2×21310305511² (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 (21310305571) 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, 5803206 + ... + 5806876.

It is an arithmetic number, because the mean of its divisors is an integer number (791169120).

Almost surely, 2^21310305511 is an apocalyptic number.

21310305511 is a deficient number, since it is larger than the sum of its proper divisors (4007106329).

21310305511 is a wasteful number, since it uses less digits than its factorization.

21310305511 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4575.

The product of its (nonzero) digits is 450, while the sum is 22.

Adding to 21310305511 its reverse (11550301312), we get a palindrome (32860606823).

The spelling of 21310305511 in words is "twenty-one billion, three hundred ten million, three hundred five thousand, five hundred eleven".