21431315511 has 6 divisors (see below), whose sum is σ = 30956344640. Its totient is φ = 14287543668.

The previous prime is 21431315497. The next prime is 21431315513. The reversal of 21431315511 is 11551313412.

21431315511 is a `hidden beast` number, since 2 + 14 + 3 + 131 + 5 + 511 = 666.

It is not a de Polignac number, because 21431315511 - 2⁶ = 21431315447 is a prime.

It is a super-3 number, since 3×21431315511³ (a number of 32 digits) contains 333 as substring. Note that it is a super-d number also for d = 2.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21431315513) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 1190628631 + ... + 1190628648.

Almost surely, 2^21431315511 is an apocalyptic number.

21431315511 is a deficient number, since it is larger than the sum of its proper divisors (9525029129).

21431315511 is a wasteful number, since it uses less digits than its factorization.

21431315511 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2381257285 (or 2381257282 counting only the distinct ones).

The product of its digits is 1800, while the sum is 27.

Adding to 21431315511 its reverse (11551313412), we get a palindrome (32982628923).

The spelling of 21431315511 in words is "twenty-one billion, four hundred thirty-one million, three hundred fifteen thousand, five hundred eleven".