21007011 has 4 divisors (see below), whose sum is σ = 28009352. Its totient is φ = 14004672.

The previous prime is 21007001. The next prime is 21007013. The reversal of 21007011 is 11070012.

It is a semiprime because it is the product of two primes.

It is not a de Polignac number, because 21007011 - 2¹⁰ = 21005987 is a prime.

It is a super-2 number, since 2×21007011² = 882589022308242, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21007013) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3501166 + ... + 3501171.

It is an arithmetic number, because the mean of its divisors is an integer number (7002338).

Almost surely, 2^21007011 is an apocalyptic number.

21007011 is a deficient number, since it is larger than the sum of its proper divisors (7002341).

21007011 is an equidigital number, since it uses as much as digits as its factorization.

21007011 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7002340.

The product of its (nonzero) digits is 14, while the sum is 12.

The square root of 21007011 is about 4583.3405939336. The cubic root of 21007011 is about 275.9231171067.

Adding to 21007011 its reverse (11070012), we get a palindrome (32077023).

The spelling of 21007011 in words is "twenty-one million, seven thousand, eleven".