21317000 has 32 divisors (see below), whose sum is σ = 49884120. Its totient is φ = 8526400.

The previous prime is 21316987. The next prime is 21317003. The reversal of 21317000 is 71312.

It can be written as a sum of positive squares in 4 ways, for example, as 14273284 + 7043716 = 3778^2 + 2654^2 .

It is not an unprimeable number, because it can be changed into a prime (21317003) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 9659 + ... + 11658.

Almost surely, 2^21317000 is an apocalyptic number.

21317000 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21317000 is an abundant number, since it is smaller than the sum of its proper divisors (28567120).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21317000 is a wasteful number, since it uses less digits than its factorization.

21317000 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 21338 (or 21324 counting only the distinct ones).

The product of its (nonzero) digits is 42, while the sum is 14.

The square root of 21317000 is about 4617.0336797559. The cubic root of 21317000 is about 277.2737110387.

Adding to 21317000 its reverse (71312), we get a palindrome (21388312).

The spelling of 21317000 in words is "twenty-one million, three hundred seventeen thousand".