21317124 has 24 divisors (see below), whose sum is σ = 49819840. Its totient is φ = 7094304.

The previous prime is 21317083. The next prime is 21317129. The reversal of 21317124 is 42171312.

It is a self number, because there is not a number n which added to its sum of digits gives 21317124.

It is not an unprimeable number, because it can be changed into a prime (21317129) 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, 10062 + ... + 11994.

Almost surely, 2^21317124 is an apocalyptic number.

It is an amenable number.

21317124 is an abundant number, since it is smaller than the sum of its proper divisors (28502716).

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

21317124 is a wasteful number, since it uses less digits than its factorization.

21317124 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2859 (or 2857 counting only the distinct ones).

The product of its digits is 336, while the sum is 21.

The square root of 21317124 is about 4617.0471082717. The cubic root of 21317124 is about 277.2742486671.

Adding to 21317124 its reverse (42171312), we get a palindrome (63488436).

The spelling of 21317124 in words is "twenty-one million, three hundred seventeen thousand, one hundred twenty-four".