21280662 has 48 divisors (see below), whose sum is σ = 50013600. Its totient is φ = 6500736.

The previous prime is 21280639. The next prime is 21280687. The reversal of 21280662 is 26608212.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 46338 + ... + 46794.

It is an arithmetic number, because the mean of its divisors is an integer number (1041950).

Almost surely, 2^21280662 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21280662, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (25006800).

21280662 is an abundant number, since it is smaller than the sum of its proper divisors (28732938).

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

21280662 is a wasteful number, since it uses less digits than its factorization.

21280662 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 677 (or 674 counting only the distinct ones).

The product of its (nonzero) digits is 2304, while the sum is 27.

The square root of 21280662 is about 4613.0967906603. The cubic root of 21280662 is about 277.1160699909.

Adding to 21280662 its reverse (26608212), we get a palindrome (47888874).

The spelling of 21280662 in words is "twenty-one million, two hundred eighty thousand, six hundred sixty-two".