21232684 has 24 divisors (see below), whose sum is σ = 41227200. Its totient is φ = 9486480.

The previous prime is 21232681. The next prime is 21232693. The reversal of 21232684 is 48623212.

It is not an unprimeable number, because it can be changed into a prime (21232681) 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 7 ways as a sum of consecutive naturals, for example, 1494 + ... + 6685.

It is an arithmetic number, because the mean of its divisors is an integer number (1717800).

Almost surely, 2^21232684 is an apocalyptic number.

It is an amenable number.

21232684 is a deficient number, since it is larger than the sum of its proper divisors (19994516).

21232684 is a wasteful number, since it uses less digits than its factorization.

21232684 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8253 (or 8251 counting only the distinct ones).

The product of its digits is 4608, while the sum is 28.

The square root of 21232684 is about 4607.8936619675. The cubic root of 21232684 is about 276.9076573165.

Adding to 21232684 its reverse (48623212), we get a palindrome (69855896).

It can be divided in two parts, 212 and 32684, that added together give a triangular number (32896 = T₂₅₆).

The spelling of 21232684 in words is "twenty-one million, two hundred thirty-two thousand, six hundred eighty-four".