21151111311 has 20 divisors (see below), whose sum is σ = 34468479144. Its totient is φ = 12818854800.

The previous prime is 21151111273. The next prime is 21151111327. The reversal of 21151111311 is 11311115112.

21151111311 is a `hidden beast` number, since 21 + 1 + 511 + 1 + 131 + 1 = 666.

It is not a de Polignac number, because 21151111311 - 2¹⁰ = 21151110287 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21151111381) by changing a digit.

It is a polite number, since it can be written in 19 ways as a sum of consecutive naturals, for example, 11868420 + ... + 11870201.

Almost surely, 2^21151111311 is an apocalyptic number.

21151111311 is a deficient number, since it is larger than the sum of its proper divisors (13317367833).

21151111311 is a wasteful number, since it uses less digits than its factorization.

21151111311 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 23738644 (or 23738635 counting only the distinct ones).

The product of its digits is 30, while the sum is 18.

Adding to 21151111311 its reverse (11311115112), we get a palindrome (32462226423).

The spelling of 21151111311 in words is "twenty-one billion, one hundred fifty-one million, one hundred eleven thousand, three hundred eleven".