21131011 has 8 divisors (see below), whose sum is σ = 23192064. Its totient is φ = 19093320.

The previous prime is 21131009. The next prime is 21131029. The reversal of 21131011 is 11013112.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 21131011 - 2¹ = 21131009 is a prime.

It is a super-3 number, since 3×21131011³ (a number of 23 digits) contains 333 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21131041) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 3915 + ... + 7588.

It is an arithmetic number, because the mean of its divisors is an integer number (2899008).

Almost surely, 2^21131011 is an apocalyptic number.

21131011 is a deficient number, since it is larger than the sum of its proper divisors (2061053).

21131011 is a wasteful number, since it uses less digits than its factorization.

21131011 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 11681.

The product of its (nonzero) digits is 6, while the sum is 10.

The square root of 21131011 is about 4596.8479417966. The cubic root of 21131011 is about 276.4649578940.

Adding to 21131011 its reverse (11013112), we get a palindrome (32144123).

The spelling of 21131011 in words is "twenty-one million, one hundred thirty-one thousand, eleven".