21030011 has 4 divisors (see below), whose sum is σ = 21052224. Its totient is φ = 21007800.

The previous prime is 21030001. The next prime is 21030043. The reversal of 21030011 is 11003012.

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21030011 is a prime.

It is a super-2 number, since 2×21030011² = 884522725320242, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21030001) 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, 9620 + ... + 11601.

It is an arithmetic number, because the mean of its divisors is an integer number (5263056).

Almost surely, 2^21030011 is an apocalyptic number.

21030011 is a deficient number, since it is larger than the sum of its proper divisors (22213).

21030011 is an equidigital number, since it uses as much as digits as its factorization.

21030011 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 22212.

The product of its (nonzero) digits is 6, while the sum is 8.

The square root of 21030011 is about 4585.8489944611. The cubic root of 21030011 is about 276.0237805947.

Adding to 21030011 its reverse (11003012), we get a palindrome (32033023).

The spelling of 21030011 in words is "twenty-one million, thirty thousand, eleven".