21317238 has 12 divisors (see below), whose sum is σ = 46187388. Its totient is φ = 7105740.

The previous prime is 21317213. The next prime is 21317249. The reversal of 21317238 is 83271312.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 592128 + ... + 592163.

It is an arithmetic number, because the mean of its divisors is an integer number (3848949).

Almost surely, 2^21317238 is an apocalyptic number.

21317238 is an abundant number, since it is smaller than the sum of its proper divisors (24870150).

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

21317238 is a wasteful number, since it uses less digits than its factorization.

21317238 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1184299 (or 1184296 counting only the distinct ones).

The product of its digits is 2016, while the sum is 27.

The square root of 21317238 is about 4617.0594538082. The cubic root of 21317238 is about 277.2747429365.

The spelling of 21317238 in words is "twenty-one million, three hundred seventeen thousand, two hundred thirty-eight".