21316472 has 16 divisors (see below), whose sum is σ = 40532400. Its totient is φ = 10507840.

The previous prime is 21316459. The next prime is 21316481. The reversal of 21316472 is 27461312.

It is a zygodrome in base 3.

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 in 3 ways as a sum of consecutive naturals, for example, 18197 + ... + 19332.

It is an arithmetic number, because the mean of its divisors is an integer number (2533275).

Almost surely, 2^21316472 is an apocalyptic number.

It is an amenable number.

21316472 is a deficient number, since it is larger than the sum of its proper divisors (19215928).

21316472 is a wasteful number, since it uses less digits than its factorization.

21316472 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 37606 (or 37602 counting only the distinct ones).

The product of its digits is 2016, while the sum is 26.

The square root of 21316472 is about 4616.9764998319. The cubic root of 21316472 is about 277.2714217589.

Adding to 21316472 its reverse (27461312), we get a palindrome (48777784).

The spelling of 21316472 in words is "twenty-one million, three hundred sixteen thousand, four hundred seventy-two".