21282740 has 24 divisors (see below), whose sum is σ = 46136832. Its totient is φ = 8238240.

The previous prime is 21282739. The next prime is 21282743. The reversal of 21282740 is 4728212.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21282743) 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, 16544 + ... + 17783.

It is an arithmetic number, because the mean of its divisors is an integer number (1922368).

Almost surely, 2^21282740 is an apocalyptic number.

21282740 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21282740 is an abundant number, since it is smaller than the sum of its proper divisors (24854092).

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

21282740 is a wasteful number, since it uses less digits than its factorization.

21282740 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 34367 (or 34365 counting only the distinct ones).

The product of its (nonzero) digits is 1792, while the sum is 26.

The square root of 21282740 is about 4613.3220134736. The cubic root of 21282740 is about 277.1250895796.

It can be divided in two parts, 21282 and 740, that added together give a palindrome (22022).

The spelling of 21282740 in words is "twenty-one million, two hundred eighty-two thousand, seven hundred forty".