21317264 has 10 divisors (see below), whose sum is σ = 41302230. Its totient is φ = 10658624.

The previous prime is 21317249. The next prime is 21317267. The reversal of 21317264 is 46271312.

It can be written as a sum of positive squares in only one way, i.e., 17707264 + 3610000 = 4208^2 + 1900^2 .

It is not an unprimeable number, because it can be changed into a prime (21317267) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 666149 + ... + 666180.

It is an arithmetic number, because the mean of its divisors is an integer number (4130223).

Almost surely, 2^21317264 is an apocalyptic number.

It is an amenable number.

21317264 is a deficient number, since it is larger than the sum of its proper divisors (19984966).

21317264 is a wasteful number, since it uses less digits than its factorization.

21317264 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1332337 (or 1332331 counting only the distinct ones).

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

The square root of 21317264 is about 4617.0622694523. The cubic root of 21317264 is about 277.2748556644.

Adding to 21317264 its reverse (46271312), we get a palindrome (67588576).

The spelling of 21317264 in words is "twenty-one million, three hundred seventeen thousand, two hundred sixty-four".