11643021 has 20 divisors (see below), whose sum is σ = 18732252. Its totient is φ = 7164288.

The previous prime is 11642959. The next prime is 11643041. The reversal of 11643021 is 12034611.

It is a happy number.

11643021 is a `hidden beast` number, since 1 + 1 + 643 + 0 + 21 = 666.

It can be written as a sum of positive squares in 2 ways, for example, as 1946025 + 9696996 = 1395^2 + 3114^2 .

It is not a de Polignac number, because 11643021 - 2⁶ = 11642957 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 11642985 and 11643003.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (11643041) 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 19 ways as a sum of consecutive naturals, for example, 4476 + ... + 6581.

Almost surely, 2^11643021 is an apocalyptic number.

It is an amenable number.

11643021 is a deficient number, since it is larger than the sum of its proper divisors (7089231).

11643021 is a wasteful number, since it uses less digits than its factorization.

11643021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 11082 (or 11073 counting only the distinct ones).

The product of its (nonzero) digits is 144, while the sum is 18.

The square root of 11643021 is about 3412.1871285145. The cubic root of 11643021 is about 226.6497409026.

Adding to 11643021 its reverse (12034611), we get a palindrome (23677632).

The spelling of 11643021 in words is "eleven million, six hundred forty-three thousand, twenty-one".