21280112 has 30 divisors (see below), whose sum is σ = 47963448. Its totient is φ = 9119712.

The previous prime is 21280099. The next prime is 21280117. The reversal of 21280112 is 21108212.

It is a happy number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21280117) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 12788 + ... + 14355.

Almost surely, 2^21280112 is an apocalyptic number.

It is an amenable number.

21280112 is an abundant number, since it is smaller than the sum of its proper divisors (26683336).

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

21280112 is a wasteful number, since it uses less digits than its factorization.

21280112 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 27165 (or 27152 counting only the distinct ones).

The product of its (nonzero) digits is 64, while the sum is 17.

The square root of 21280112 is about 4613.0371773919. The cubic root of 21280112 is about 277.1136826098.

Adding to 21280112 its reverse (21108212), we get a palindrome (42388324).

The spelling of 21280112 in words is "twenty-one million, two hundred eighty thousand, one hundred twelve".