21316473 has 16 divisors (see below), whose sum is σ = 31651200. Its totient is φ = 14178960.

The previous prime is 21316459. The next prime is 21316481. The reversal of 21316473 is 37461312.

21316473 is a `hidden beast` number, since 2 + 13 + 1 + 647 + 3 = 666.

It is not a de Polignac number, because 21316473 - 2⁹ = 21315961 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is not an unprimeable number, because it can be changed into a prime (21316483) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 22183 + ... + 23123.

It is an arithmetic number, because the mean of its divisors is an integer number (1978200).

Almost surely, 2^21316473 is an apocalyptic number.

It is an amenable number.

21316473 is a deficient number, since it is larger than the sum of its proper divisors (10334727).

21316473 is an equidigital number, since it uses as much as digits as its factorization.

21316473 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1789 (or 1783 counting only the distinct ones).

The product of its digits is 3024, while the sum is 27.

The square root of 21316473 is about 4616.9766081279. The cubic root of 21316473 is about 277.2714260947.

Adding to 21316473 its reverse (37461312), we get a palindrome (58777785).

The spelling of 21316473 in words is "twenty-one million, three hundred sixteen thousand, four hundred seventy-three".