21317268 has 24 divisors (see below), whose sum is σ = 56846272. Its totient is φ = 6090624.

The previous prime is 21317267. The next prime is 21317327. The reversal of 21317268 is 86271312.

It is a congruent number.

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 in 7 ways as a sum of consecutive naturals, for example, 126805 + ... + 126972.

Almost surely, 2^21317268 is an apocalyptic number.

21317268 is a gapful number since it is divisible by the number (28) formed by its first and last digit.

It is an amenable number.

21317268 is an abundant number, since it is smaller than the sum of its proper divisors (35529004).

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

21317268 is a wasteful number, since it uses less digits than its factorization.

21317268 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 253791 (or 253789 counting only the distinct ones).

The product of its digits is 4032, while the sum is 30.

The square root of 21317268 is about 4617.0627026282. The cubic root of 21317268 is about 277.2748730071.

The spelling of 21317268 in words is "twenty-one million, three hundred seventeen thousand, two hundred sixty-eight".