21152866 has 16 divisors (see below), whose sum is σ = 36550656. Its totient is φ = 8993376.

The previous prime is 21152849. The next prime is 21152869. The reversal of 21152866 is 66825112.

It is not an unprimeable number, because it can be changed into a prime (21152869) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 4171 + ... + 7726.

It is an arithmetic number, because the mean of its divisors is an integer number (2284416).

Almost surely, 2^21152866 is an apocalyptic number.

21152866 is a deficient number, since it is larger than the sum of its proper divisors (15397790).

21152866 is a wasteful number, since it uses less digits than its factorization.

21152866 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 12033.

The product of its digits is 5760, while the sum is 31.

The square root of 21152866 is about 4599.2244998478. The cubic root of 21152866 is about 276.5602374462.

Adding to 21152866 its reverse (66825112), we get a palindrome (87977978).

The spelling of 21152866 in words is "twenty-one million, one hundred fifty-two thousand, eight hundred sixty-six".