21280382 has 16 divisors (see below), whose sum is σ = 33454080. Its totient is φ = 10133112.

The previous prime is 21280381. The next prime is 21280387. The reversal of 21280382 is 28308212.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21280381) 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, 11219 + ... + 12977.

It is an arithmetic number, because the mean of its divisors is an integer number (2090880).

Almost surely, 2^21280382 is an apocalyptic number.

21280382 is a deficient number, since it is larger than the sum of its proper divisors (12173698).

21280382 is a wasteful number, since it uses less digits than its factorization.

21280382 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2047.

The product of its (nonzero) digits is 1536, while the sum is 26.

The square root of 21280382 is about 4613.0664421836. The cubic root of 21280382 is about 277.1148546021.

Adding to 21280382 its reverse (28308212), we get a palindrome (49588594).

The spelling of 21280382 in words is "twenty-one million, two hundred eighty thousand, three hundred eighty-two".