21326672 has 10 divisors (see below), whose sum is σ = 41320458. Its totient is φ = 10663328.

The previous prime is 21326663. The next prime is 21326699. The reversal of 21326672 is 27662312.

It can be written as a sum of positive squares in only one way, i.e., 19749136 + 1577536 = 4444^2 + 1256^2 .

It is a congruent number.

It is an unprimeable number.

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 as a sum of consecutive naturals, namely, 666443 + ... + 666474.

Almost surely, 2^21326672 is an apocalyptic number.

It is an amenable number.

21326672 is a deficient number, since it is larger than the sum of its proper divisors (19993786).

21326672 is a wasteful number, since it uses less digits than its factorization.

21326672 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1332925 (or 1332919 counting only the distinct ones).

The product of its digits is 6048, while the sum is 29.

The square root of 21326672 is about 4618.0809867303. The cubic root of 21326672 is about 277.3156397941.

Adding to 21326672 its reverse (27662312), we get a palindrome (48988984).

The spelling of 21326672 in words is "twenty-one million, three hundred twenty-six thousand, six hundred seventy-two".