21282318 has 32 divisors (see below), whose sum is σ = 49785600. Its totient is φ = 6720408.

The previous prime is 21282311. The next prime is 21282319. The reversal of 21282318 is 81328212.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a junction number, because it is equal to n+sod(n) for n = 21282291 and 21282300.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21282311) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 9346 + ... + 11397.

It is an arithmetic number, because the mean of its divisors is an integer number (1555800).

Almost surely, 2^21282318 is an apocalyptic number.

21282318 is an abundant number, since it is smaller than the sum of its proper divisors (28503282).

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

21282318 is a wasteful number, since it uses less digits than its factorization.

21282318 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 20773 (or 20767 counting only the distinct ones).

The product of its digits is 1536, while the sum is 27.

The square root of 21282318 is about 4613.2762761404. The cubic root of 21282318 is about 277.1232579301.

It can be divided in two parts, 21282 and 318, that multiplied together give a palindrome (6767676).

The spelling of 21282318 in words is "twenty-one million, two hundred eighty-two thousand, three hundred eighteen".