21143011 has 4 divisors (see below), whose sum is σ = 21180232. Its totient is φ = 21105792.

The previous prime is 21143009. The next prime is 21143039. The reversal of 21143011 is 11034112.

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

It is a cyclic number.

It is not a de Polignac number, because 21143011 - 2¹ = 21143009 is a prime.

It is a super-2 number, since 2×21143011² = 894053828292242, which contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21142982 and 21143000.

It is not an unprimeable number, because it can be changed into a prime (21143051) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 17745 + ... + 18898.

It is an arithmetic number, because the mean of its divisors is an integer number (5295058).

Almost surely, 2^21143011 is an apocalyptic number.

21143011 is a deficient number, since it is larger than the sum of its proper divisors (37221).

21143011 is an equidigital number, since it uses as much as digits as its factorization.

21143011 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 37220.

The product of its (nonzero) digits is 24, while the sum is 13.

The square root of 21143011 is about 4598.1529987594. The cubic root of 21143011 is about 276.5172814939.

Adding to 21143011 its reverse (11034112), we get a palindrome (32177123).

The spelling of 21143011 in words is "twenty-one million, one hundred forty-three thousand, eleven".