21124312011 has 36 divisors (see below), whose sum is σ = 33595272256. Its totient is φ = 12781121760.

The previous prime is 21124312007. The next prime is 21124312019. The reversal of 21124312011 is 11021342112.

21124312011 is a `hidden beast` number, since 21 + 12 + 431 + 201 + 1 = 666.

It is not a de Polignac number, because 21124312011 - 2² = 21124312007 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21124312019) by changing a digit.

It is a polite number, since it can be written in 35 ways as a sum of consecutive naturals, for example, 645045 + ... + 677001.

Almost surely, 2^21124312011 is an apocalyptic number.

21124312011 is a deficient number, since it is larger than the sum of its proper divisors (12470960245).

21124312011 is a wasteful number, since it uses less digits than its factorization.

21124312011 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 32592 (or 32578 counting only the distinct ones).

The product of its (nonzero) digits is 96, while the sum is 18.

Adding to 21124312011 its reverse (11021342112), we get a palindrome (32145654123).

The spelling of 21124312011 in words is "twenty-one billion, one hundred twenty-four million, three hundred twelve thousand, eleven".